* posix/bits/unistd.h: Avoid calling __*_chk variants if we can

	determine the call will never trigger a failure.

	* sysdeps/i386/i686/memset_chk.S: Remove alias and warning.
	* sysdeps/x86_64/memset_chk.S: Likewise.

2005-02-24  Roland McGrath  <roland@redhat.com>

	* debug/Versions (libc: GLIBC_2.4): Remove
	__memset_zero_constant_len_parameter.
	* sysdeps/generic/memset_chk.c: Remove alias and warning.
	* misc/sys/cdefs.h (__warndecl): New macro.
	* debug/warning-nop.c: New file.
	* string/bits/string3.h (memset): Call __warn_memset_zero_len with no
	arguments, instead of calling __memset_zero_constant_len_parameter.
	Use __warndecl for __warn_memset_zero_len.
	* debug/Makefile (routines): Add $(static-only-routines).
	(static-only-routines): New variable.