stdio: Remove the usage of $(fno-unit-at-a-time) for siglist.c

The siglist.c is built with -fno-toplevel-reorder to avoid compiler
to reorder the compat assembly directives due an assembler
issue [1] (fixed on 2.39).

This patch removes the compiler flags by split the compat symbol
generation in two phases.  First the __sys_siglist and __sys_sigabbrev
without any compat symbol directive is preprocessed to generate an
assembly source code.  This generate assembly is then used as input
on a platform agnostic siglist.S which then creates the compat
definitions.  This prevents compiler to move any compat directive
prior the _sys_errlist definition itself.

Checked on a make check run-built-tests=no on all affected ABIs.

Reviewed-by: Fangrui Song <maskray@google.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/include/signal.h b/include/signal.h
index 2a278697c1..73f18dddd7 100644
--- a/include/signal.h
+++ b/include/signal.h
@@ -14,10 +14,8 @@ libc_hidden_proto (__sigpause)
 libc_hidden_proto (raise)
 libc_hidden_proto (__libc_current_sigrtmin)
 libc_hidden_proto (__libc_current_sigrtmax)
-extern const char * const __sys_siglist[_NSIG];
-libc_hidden_proto (__sys_siglist)
-extern const char * const __sys_sigabbrev[_NSIG];
-libc_hidden_proto (__sys_sigabbrev)
+extern const char * const __sys_siglist[_NSIG] attribute_hidden;
+extern const char * const __sys_sigabbrev[_NSIG] attribute_hidden;
 
 /* Now define the internal interfaces.  */
 extern __sighandler_t __bsd_signal (int __sig, __sighandler_t __handler);