[gcc r16-6008] libsanitizer: Restore local sanitizer_redefine_builtins.h patch

[Rainer Orth]

https://gcc.gnu.org/g:203d4dd09ba83121e447ce93ba98175b68d955f6

commit r16-6008-g203d4dd09ba83121e447ce93ba98175b68d955f6
Author: Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
Date:   Wed Dec 10 09:24:53 2025 +0100

    libsanitizer: Restore local sanitizer_redefine_builtins.h patch
    
    The recent libsanitizer update broke the Solaris/SPARC build with the
    native assembler: many files don't compile any longer like
    
    /usr/bin/as: "/var/tmp//ccYsT60a.s", line 5: error: unknown opcode ".set"
    /usr/bin/as: "/var/tmp//ccYsT60a.s", line 5: error: statement syntax
    /usr/bin/as: "/var/tmp//ccYsT60a.s", line 6: error: unknown opcode ".set"
    /usr/bin/as: "/var/tmp//ccYsT60a.s", line 6: error: statement syntax
    /usr/bin/as: "/var/tmp//ccYsT60a.s", line 7: error: unknown opcode ".set"
    /usr/bin/as: "/var/tmp//ccYsT60a.s", line 7: error: statement syntax
    
    This happens because sanitizer_common/sanitizer_redefine_builtins.h lost
    a local patch that guards use of .set in asm by HAVE_AS_SYM_ASSIGN.
    This patch restores that patch.
    
    Although the Darwin assembler accepts .set (thus HAVE_AS_SYM_ASSIGN is
    defined), the __APPLE__ guard is kept to guard against the link failures
    that prompted its upstreadm addition in LLVM commit
    
    commit cfdbbb8fcc62f75dcf0b251dfab63353f3921227
    Author: Dan Blackwell <dan_blackwell@apple.com>
    Date:   Fri Aug 15 09:13:26 2025 +0100
    
        [sanitizer_common] Disable sanitizer_redefine_builtins on Apple platforms (#153381)
    
    even though they didn't happen in the GCC build.
    
    It also keeps the _AIX guard due to LLVM commit
    
    commit d7c6cad744bc7ed28535dc6f75629902eda559ea
    Author: Jake Egan <Jake.egan@ibm.com>
    Date:   Wed Jun 11 20:22:15 2025 -0400
    
        [sanitizer_common] Implement interception on AIX (#138606)
    
    Bootstrapped without regressions on sparc-sun-solaris2.11 with gas and
    as, i386-pc-solaris2.11, x86_64-pc-linux-gnu, and
    x86_64-apple-darwin25.1.0.

Diff:
---
 libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h b/libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h
index 7d8891117657..26f4b48e4fd2 100644
--- a/libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h
+++ b/libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h
@@ -15,7 +15,8 @@
 #    define SANITIZER_REDEFINE_BUILTINS_H
 
 // The asm hack only works with GCC and Clang.
-#    if !defined(_WIN32) && !defined(_AIX) && !defined(__APPLE__)
+#if !defined(_WIN32) && !defined(_AIX) && !defined(__APPLE__) &&               \
+    defined(HAVE_AS_SYM_ASSIGN)
 
 asm(R"(
     .set memcpy, __sanitizer_internal_memcpy