Without the asm redirects, strchr et al. are not const-correct.
libc++ has a wrapper header that works with and without
__CORRECT_ISO_CPP_STRING_H_PROTO (using a Clang extension). But when
Clang is used with libstdc++ or just C headers, the overloaded functions
with the correct types are not declared.
This change does not impact current GCC (with libstdc++ or libc++).
(cherry picked from commit
953ceff17a4a15b10cfdd5edc3c8cae4884c8ec3)
[25203] libio: Disable vtable validation for pre-2.1 interposed handles
[25204] Ignore LD_PREFER_MAP_32BIT_EXEC for SUID programs
[25225] ld.so fails to link on x86 if GCC defaults to -fcf-protection
+ [25232] No const correctness for strchr et al. for Clang++
Security related changes:
#include <stddef.h>
/* Tell the caller that we provide correct C++ prototypes. */
-#if defined __cplusplus && __GNUC_PREREQ (4, 4)
+#if defined __cplusplus && (__GNUC_PREREQ (4, 4) \
+ || __glibc_clang_prereq (3, 5))
# define __CORRECT_ISO_CPP_STRING_H_PROTO
#endif