[PATCH v2] Remove defines to builtins in string2.h

[Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>]

As discussed in https://sourceware.org/ml/libc-alpha/2016-11/msg00625.html,
for C90 functions there is no need to use define to use the GCC builtin as
an optimization.  Also other headers already ensure (most) non-C90 symbols
are redirected to avoid name space clashes.

So remove the defines for strchr, __stpcpy, stpcpy, strncpy, strncat, strcspn,
strspn, strpbrk and strsep from string/bits/string2.h. The strncat define only
uses the #else as _USE_STRING_ARCH_strchr is never defined unless
_HAVE_STRING_ARCH_strncat is defined too.

elf/check-localplt and linknamespace test pass so the redirections weren't
required or useful.

ChangeLog:
2015-11-22  Wilco Dijkstra  <wdijkstr@arm.com>

	* string/bits/string2.h (strchr) Remove define.
	(stpcpy): Likewise.
	(__stpcpy): Likewise.
	(strncpy): Likewise.
	(strncat): Likewise.
	(strcspn): Likewise.
	(strspn): Likewise.
	(strpbrk): Likewise.
	(strsep): Likewise.
 --
diff --git a/string/bits/string2.h b/string/bits/string2.h
index 8fa35d52e7c8e3ff592573fa64472da526e8616d..941e9bff015a89908dbf61044a1787bcb4026b89 100644
--- a/string/bits/string2.h
+++ b/string/bits/string2.h
@@ -58,45 +58,6 @@
 #endif
 
 
-#ifndef _HAVE_STRING_ARCH_strchr
-# define strchr(s, c) __builtin_strchr (s, c)
-#endif
-
-
-/* Copy SRC to DEST, returning pointer to final NUL byte.  */
-#ifdef __USE_GNU
-# ifndef _HAVE_STRING_ARCH_stpcpy
-#  define __stpcpy(dest, src) __builtin_stpcpy (dest, src)
-/* In glibc we use this function frequently but for namespace reasons
-   we have to use the name `__stpcpy'.  */
-#  define stpcpy(dest, src) __stpcpy (dest, src)
-# endif
-#endif
-
-
-/* Copy no more than N characters of SRC to DEST.  */
-#ifndef _HAVE_STRING_ARCH_strncpy
-# define strncpy(dest, src, n) __builtin_strncpy (dest, src, n)
-#endif
-
-
-/* Append no more than N characters from SRC onto DEST.  */
-#ifndef _HAVE_STRING_ARCH_strncat
-# ifdef _USE_STRING_ARCH_strchr
-#  define strncat(dest, src, n) \
-  (__extension__ ({ char *__dest = (dest);				      \
-		    __builtin_constant_p (src) && __builtin_constant_p (n)    \
-		    ? (strlen (src) < ((size_t) (n))			      \
-		       ? strcat (__dest, src)				      \
-		       : (*((char *) __mempcpy (strchr (__dest, '\0'),	      \
-						src, n)) = '\0', __dest))     \
-		    : strncat (dest, src, n); }))
-# else
-#  define strncat(dest, src, n) __builtin_strncat (dest, src, n)
-# endif
-#endif
-
-
 /* Compare characters of S1 and S2.  */
 #ifndef _HAVE_STRING_ARCH_strcmp
 # define strcmp(s1, s2) \
@@ -155,32 +116,6 @@
 #endif
 
 
-/* Return the length of the initial segment of S which
-   consists entirely of characters not in REJECT.  */
-#ifndef _HAVE_STRING_ARCH_strcspn
-# define strcspn(s, reject) __builtin_strcspn (s, reject)
-#endif
-
-
-/* Return the length of the initial segment of S which
-   consists entirely of characters in ACCEPT.  */
-#ifndef _HAVE_STRING_ARCH_strspn
-# define strspn(s, accept) __builtin_strspn (s, accept)
-#endif
-
-
-/* Find the first occurrence in S of any character in ACCEPT.  */
-#ifndef _HAVE_STRING_ARCH_strpbrk
-# define strpbrk(s, accept) __builtin_strpbrk (s, accept)
-#endif
-
-
-#if !defined _HAVE_STRING_ARCH_strsep
-# ifdef __USE_MISC
-#  define strsep(s, reject) __strsep (s, reject)
-# endif
-#endif
-
 /* We need the memory allocation functions for inline strdup().
    Referring to stdlib.h (even minimally) is not allowed
    in any of the tight standards compliant modes.  */