* debug/pread64_chk.c: Use __libc_pread64 instead of __pread64.

* debug/pread64_chk.c: Use __libc_pread64 instead of __pread64.

	* sysdeps/posix/posix_fallocate64.c: Likewise.
	* include/string.h: Use libc_hidden_proto for strnlen.
	* sysdeps/generic/strnlen.c: Add libc_hidden_def.
	* include/libintl.h: Use libc_hidden_proto for __dcgettext.
	* intl/dcgettext.c: Add libc_hidden_def.
	* include/execinfo.h: Add libc_hidden_proto for __backtrace and
	__backtrace_symbols_fd.
	* sysdeps/generic/backtrace.c: Add libc_hidden_def.
	* sysdeps/generic/backtracesymsfd.c: Likewise.
	* sysdeps/generic/elf/backtracesymsfd.c: Likewise.
	* sysdeps/i386/backtrace.c: Likewise.
	* sysdeps/ia64/backtrace.c: Likewise.
	* sysdeps/powerpc/powerpc32/backtrace.c: Likewise.
	* sysdeps/powerpc/powerpc64/backtrace.c: Likewise.
	* sysdeps/s390/s390-32/backtrace.c: Likewise.
	* sysdeps/s390/s390-64/backtrace.c: Likewise.