[gcc r12-3294] Fix arm target build with inhibit_libc

[gcc r12-3294] Fix arm target build with inhibit_libc

[Sebastian Huber]

https://gcc.gnu.org/g:7a6f40d0452ec76e126c2612dcfa32f3c73e2315

commit r12-3294-g7a6f40d0452ec76e126c2612dcfa32f3c73e2315
Author: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date:   Mon Aug 30 13:52:11 2021 +0200

    Fix arm target build with inhibit_libc
    
    Do not declare abort in "libgcc/unwind-arm-common.inc" since it is already
    provided by "tsystem.h".  It fixes the following build error:
    
    In file included from libgcc/config/arm/unwind-arm.c:144:
    libgcc/unwind-arm-common.inc:55:24: error: macro "abort" passed 1 arguments, but takes just 0
       55 | extern void abort (void);
    
    libgcc/
    
            * unwind-arm-common.inc (abort): Remove.

Diff:
---
 libgcc/unwind-arm-common.inc | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc
index c9b70c10d4f..77ec02ec811 100644
--- a/libgcc/unwind-arm-common.inc
+++ b/libgcc/unwind-arm-common.inc
@@ -50,10 +50,6 @@
 #define ARM_SIGCONTEXT_R0		0xc
 #endif
 
-/* We add a prototype for abort here to avoid creating a dependency on
-   target headers.  */
-extern void abort (void);
-
 /* Definitions for C++ runtime support routines.  We make these weak
    declarations to avoid pulling in libsupc++ unnecessarily.  */
 typedef unsigned char bool;