Wrap <stdlib.h> so that calls go direct and the symbols not in the

C standard are all weak.
Apply __{BEGIN,END}_HIDDEN_DECLS to gdtoa{,imp}.h, hiding the
arch-specific __strtorx, __ULtox_D2A, __strtorQ, __ULtoQ_D2A symbols.

src/lib/libc/crypt/arc4random.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random.c,v 1.53 2015/09/10 18:53:50 bcook Exp $	*/
+/*	$OpenBSD: arc4random.c,v 1.54 2015/09/13 08:31:47 guenther Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -186,6 +186,7 @@ arc4random(void)
 	_ARC4_UNLOCK();
 	return val;
 }
+DEF_WEAK(arc4random);
 
 void
 arc4random_buf(void *buf, size_t n)
@@ -194,3 +195,4 @@ arc4random_buf(void *buf, size_t n)
 	_rs_random_buf(buf, n);
 	_ARC4_UNLOCK();
 }
+DEF_WEAK(arc4random_buf);

src/lib/libc/crypt/arc4random_uniform.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_uniform.c,v 1.1 2014/07/12 13:24:54 deraadt Exp $	*/
+/*	$OpenBSD: arc4random_uniform.c,v 1.2 2015/09/13 08:31:47 guenther Exp $	*/
 
 /*
  * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
@@ -54,3 +54,4 @@ arc4random_uniform(uint32_t upper_bound)
 
 	return r % upper_bound;
 }
+DEF_WEAK(arc4random_uniform);

src/lib/libc/stdlib/abort.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: abort.c,v 1.17 2014/05/14 21:54:20 tedu Exp $ */
+/*	$OpenBSD: abort.c,v 1.18 2015/09/13 08:31:47 guenther Exp $ */
 /*
  * Copyright (c) 1985 Regents of the University of California.
  * All rights reserved.
@@ -61,3 +61,4 @@ abort(void)
 	(void)raise(SIGABRT);
 	_exit(1);
 }
+DEF_STRONG(abort);

src/lib/libc/stdlib/abs.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: abs.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: abs.c,v 1.6 2015/09/13 08:31:47 guenther Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -35,3 +35,4 @@ abs(int j)
 {
 	return(j < 0 ? -j : j);
 }
+DEF_STRONG(abs);

src/lib/libc/stdlib/atoi.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: atoi.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: atoi.c,v 1.6 2015/09/13 08:31:47 guenther Exp $ */
 /*
  * Copyright (c) 1988 Regents of the University of California.
  * All rights reserved.
@@ -35,3 +35,4 @@ atoi(const char *str)
 {
 	return((int)strtol(str, (char **)NULL, 10));
 }
+DEF_STRONG(atoi);

src/lib/libc/stdlib/div.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: div.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: div.c,v 1.6 2015/09/13 08:31:47 guenther Exp $ */
 /*
  * Copyright (c) 1990 Regents of the University of California.
  * All rights reserved.
@@ -69,3 +69,4 @@ div(int num, int denom)
 	}
 	return (r);
 }
+DEF_STRONG(div);

src/lib/libc/stdlib/erand48.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: erand48.c,v 1.3 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: erand48.c,v 1.4 2015/09/13 08:31:47 guenther Exp $ */
 /*
  * Copyright (c) 1993 Martin Birgmeier
  * All rights reserved.
@@ -22,3 +22,4 @@ erand48(unsigned short xseed[3])
 	       ldexp((double) xseed[1], -32) +
 	       ldexp((double) xseed[2], -16);
 }
+DEF_WEAK(erand48);

src/lib/libc/stdlib/exit.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: exit.c,v 1.12 2007/09/03 14:40:16 millert Exp $ */
+/*	$OpenBSD: exit.c,v 1.13 2015/09/13 08:31:47 guenther Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -57,3 +57,4 @@ exit(int status)
 	__cxa_finalize(NULL);
 	_exit(status);
 }
+DEF_STRONG(exit);

src/lib/libc/stdlib/getenv.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: getenv.c,v 1.10 2010/08/23 22:31:50 millert Exp $ */
+/*	$OpenBSD: getenv.c,v 1.11 2015/09/13 08:31:47 guenther Exp $ */
 /*
  * Copyright (c) 1987, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -31,7 +31,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-char *__findenv(const char *name, int len, int *offset);
 
 /*
  * __findenv --
@@ -79,3 +78,4 @@ getenv(const char *name)
 		;
 	return (__findenv(name, (int)(np - name), &offset));
 }
+DEF_STRONG(getenv);

src/lib/libc/stdlib/lcong48.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: lcong48.c,v 1.5 2015/08/27 04:33:31 guenther Exp $ */
+/*	$OpenBSD: lcong48.c,v 1.6 2015/09/13 08:31:47 guenther Exp $ */
 /*
  * Copyright (c) 1993 Martin Birgmeier
  * All rights reserved.
@@ -33,3 +33,4 @@ lcong48_deterministic(unsigned short p[7])
 	__rand48_mult[2] = p[5];
 	__rand48_add = p[6];
 }
+DEF_WEAK(lcong48_deterministic);

src/lib/libc/stdlib/malloc.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: malloc.c,v 1.174 2015/04/06 09:18:51 tedu Exp $	*/
+/*	$OpenBSD: malloc.c,v 1.175 2015/09/13 08:31:47 guenther Exp $	*/
 /*
  * Copyright (c) 2008, 2010, 2011 Otto Moerbeek <otto@drijf.net>
  * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org>
@@ -211,6 +211,7 @@ extern char	*__progname;
 
 #ifdef MALLOC_STATS
 void malloc_dump(int);
+PROTO_NORMAL(malloc_dump);
 static void malloc_exit(void);
 #define CALLER	__builtin_return_address(0)
 #else
@@ -1186,6 +1187,7 @@ malloc(size_t size)
 		errno = saved_errno;
 	return r;
 }
+DEF_STRONG(malloc);
 
 static void
 ofree(void *p)
@@ -1289,6 +1291,7 @@ free(void *ptr)
 	_MALLOC_UNLOCK();
 	errno = saved_errno;
 }
+DEF_STRONG(free);
 
 
 static void *
@@ -1429,6 +1432,7 @@ realloc(void *ptr, size_t size)
 		errno = saved_errno;
 	return r;
 }
+DEF_STRONG(realloc);
 
 
 /*
@@ -1476,6 +1480,7 @@ calloc(size_t nmemb, size_t size)
 		errno = saved_errno;
 	return r;
 }
+DEF_STRONG(calloc);
 
 static void *
 mapalign(struct dir_info *d, size_t alignment, size_t sz, int zero_fill)
@@ -1609,6 +1614,7 @@ err:
 	errno = saved_errno;
 	return res;
 }
+DEF_STRONG(posix_memalign);
 
 #ifdef MALLOC_STATS
 
@@ -1853,6 +1859,7 @@ malloc_dump(int fd)
 	malloc_dump1(fd, pool);
 	errno = saved_errno;
 }
+DEF_WEAK(malloc_dump);
 
 static void
 malloc_exit(void)

src/lib/libc/stdlib/qsort.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: qsort.c,v 1.12 2014/06/12 14:54:25 millert Exp $ */
+/*	$OpenBSD: qsort.c,v 1.13 2015/09/13 08:31:47 guenther Exp $ */
 /*-
  * Copyright (c) 1992, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -149,3 +149,4 @@ loop:	SWAPINIT(a, es);
 	}
 /*		qsort(pn - r, r / es, es, cmp);*/
 }
+DEF_STRONG(qsort);

src/lib/libc/stdlib/rand.c

@@ -39,6 +39,7 @@ rand_r(u_int *seed)
 	*seed = *seed * 1103515245 + 12345;
 	return (*seed % ((u_int)RAND_MAX + 1));
 }
+DEF_WEAK(rand_r);
 
 #if defined(APIWARN)
 __warn_references(rand_r,

src/lib/libc/stdlib/reallocarray.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $	*/
+/*	$OpenBSD: reallocarray.c,v 1.3 2015/09/13 08:31:47 guenther Exp $	*/
 /*
  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
  *
@@ -36,3 +36,4 @@ reallocarray(void *optr, size_t nmemb, size_t size)
 	}
 	return realloc(optr, size * nmemb);
 }
+DEF_WEAK(reallocarray);

src/lib/libc/stdlib/setenv.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: setenv.c,v 1.15 2014/10/08 05:33:31 deraadt Exp $ */
+/*	$OpenBSD: setenv.c,v 1.16 2015/09/13 08:31:47 guenther Exp $ */
 /*
  * Copyright (c) 1987 Regents of the University of California.
  * All rights reserved.
@@ -32,8 +32,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-char *__findenv(const char *name, int len, int *offset);
-
 extern char **environ;
 static char **lastenv;				/* last value of environ */
 
@@ -81,6 +79,7 @@ putenv(char *str)
 	environ[cnt + 1] = NULL;
 	return (0);
 }
+DEF_WEAK(putenv);
 
 /*
  * setenv --
@@ -147,6 +146,7 @@ setenv(const char *name, const char *value, int rewrite)
 		;
 	return (0);
 }
+DEF_WEAK(setenv);
 
 /*
  * unsetenv(name) --
@@ -178,3 +178,4 @@ unsetenv(const char *name)
 	}
 	return (0);
 }
+DEF_WEAK(unsetenv);

src/lib/libc/stdlib/srand48.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: srand48.c,v 1.5 2015/08/27 04:33:31 guenther Exp $ */
+/*	$OpenBSD: srand48.c,v 1.6 2015/09/13 08:31:48 guenther Exp $ */
 /*
  * Copyright (c) 1993 Martin Birgmeier
  * All rights reserved.
@@ -35,3 +35,4 @@ srand48_deterministic(long seed)
 	__rand48_mult[2] = RAND48_MULT_2;
 	__rand48_add = RAND48_ADD;
 }
+DEF_WEAK(srand48_deterministic);

src/lib/libc/stdlib/strtol.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: strtol.c,v 1.10 2014/09/13 20:10:12 schwarze Exp $ */
+/*	$OpenBSD: strtol.c,v 1.11 2015/09/13 08:31:48 guenther Exp $ */
 /*
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -148,3 +148,4 @@ strtol(const char *nptr, char **endptr, int base)
 		*endptr = (char *) (any ? s - 1 : nptr);
 	return (acc);
 }
+DEF_STRONG(strtol);

src/lib/libc/stdlib/strtoll.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: strtoll.c,v 1.8 2014/09/13 20:10:12 schwarze Exp $ */
+/*	$OpenBSD: strtoll.c,v 1.9 2015/09/13 08:31:48 guenther Exp $ */
 /*
  * Copyright (c) 1992 The Regents of the University of California.
  * All rights reserved.
@@ -151,5 +151,6 @@ strtoll(const char *nptr, char **endptr, int base)
 		*endptr = (char *) (any ? s - 1 : nptr);
 	return (acc);
 }
+DEF_STRONG(strtoll);
 
-__strong_alias(strtoq, strtoll);
+__weak_alias(strtoq, strtoll);

src/lib/libc/stdlib/strtonum.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: strtonum.c,v 1.7 2013/04/17 18:40:58 tedu Exp $	*/
+/*	$OpenBSD: strtonum.c,v 1.8 2015/09/13 08:31:48 guenther Exp $	*/
 
 /*
  * Copyright (c) 2004 Ted Unangst and Todd Miller
@@ -63,3 +63,4 @@ strtonum(const char *numstr, long long minval, long long maxval,
 
 	return (ll);
 }
+DEF_WEAK(strtonum);

src/lib/libc/stdlib/strtoul.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: strtoul.c,v 1.9 2014/09/13 20:10:12 schwarze Exp $ */
+/*	$OpenBSD: strtoul.c,v 1.10 2015/09/13 08:31:48 guenther Exp $ */
 /*
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -107,3 +107,4 @@ strtoul(const char *nptr, char **endptr, int base)
 		*endptr = (char *) (any ? s - 1 : nptr);
 	return (acc);
 }
+DEF_STRONG(strtoul);

src/lib/libc/stdlib/strtoull.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: strtoull.c,v 1.7 2014/09/13 20:10:12 schwarze Exp $ */
+/*	$OpenBSD: strtoull.c,v 1.8 2015/09/13 08:31:48 guenther Exp $ */
 /*
  * Copyright (c) 1992 The Regents of the University of California.
  * All rights reserved.
@@ -109,5 +109,6 @@ strtoull(const char *nptr, char **endptr, int base)
 		*endptr = (char *) (any ? s - 1 : nptr);
 	return (acc);
 }
+DEF_STRONG(strtoull);
 
-__strong_alias(strtouq, strtoull);
+__weak_alias(strtouq, strtoull);

src/lib/libc/stdlib/system.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: system.c,v 1.8 2005/08/08 08:05:37 espie Exp $ */
+/*	$OpenBSD: system.c,v 1.9 2015/09/13 08:31:48 guenther Exp $ */
 /*
  * Copyright (c) 1988 The Regents of the University of California.
  * All rights reserved.
@@ -72,3 +72,4 @@ system(const char *command)
 	(void)signal(SIGQUIT, quitsave);
 	return (pid == -1 ? -1 : pstat);
 }
+DEF_STRONG(system);