[glibc] Build raise with -fasynchronous-unwind-tables.

[Joseph Myers <jsm28@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=352bb99754ae7c83ff1b974f9c52244e974c9410

commit 352bb99754ae7c83ff1b974f9c52244e974c9410
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Fri Jan 24 17:23:47 2020 +0000

    Build raise with -fasynchronous-unwind-tables.
    
    In testing glibc for Arm and MIPS, I see:
    
    FAIL: misc/tst-sigcontext-get_pc
    
    If this test - backtracing through a call to raise - is valid, then
    raise needs to be built with -fasynchronous-unwind-tables (as the test
    itself is) to have the required unwind information for that
    backtracing to work.  Adding that option, which this patch does,
    causes the test for pass for Arm.  For MIPS, the test still does not
    pass (the backtrace has an address that is 2 bytes after the "address
    in signal handler", for unknown reasons), although the patch allows a
    longer backtrace to be produced.

Diff:
---
 signal/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/signal/Makefile b/signal/Makefile
index 7da67de..37de438 100644
--- a/signal/Makefile
+++ b/signal/Makefile
@@ -52,6 +52,7 @@ tests		:= tst-signal tst-sigset tst-sigsimple tst-raise tst-sigset2 \
 
 include ../Rules
 
+CFLAGS-raise.c += -fasynchronous-unwind-tables
 CFLAGS-sigpause.c += -fexceptions
 CFLAGS-sigsuspend.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-sigtimedwait.c += -fexceptions -fasynchronous-unwind-tables