[glibc] hurd: Fix restoring SSE state on signal

[Samuel Thibault]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=ce61fcf7022c5344bd8311daab312fb69506d1a7

commit ce61fcf7022c5344bd8311daab312fb69506d1a7
Author: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date:   Sun Nov 16 01:32:22 2025 +0100

    hurd: Fix restoring SSE state on signal
    
    mach_port_mod_refs() needs to avoid using SSE&MMX for __sigreturn2 to be
    able to use it without thrashing SSE&MMX.

Diff:
---
 sysdeps/mach/hurd/x86/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sysdeps/mach/hurd/x86/Makefile b/sysdeps/mach/hurd/x86/Makefile
index 29371f6c9a..27c4b06590 100644
--- a/sysdeps/mach/hurd/x86/Makefile
+++ b/sysdeps/mach/hurd/x86/Makefile
@@ -14,3 +14,8 @@ endif
 ifeq ($(subdir),stdlib)
 gen-as-const-headers += ucontext_i.sym
 endif
+
+ifeq ($(subdir),mach)
+# Avoid SSE&MMX to avoid __sigreturn2 thrashing it
+CFLAGS-RPC_mach_port_mod_refs.c = -mno-sse -mno-mmx
+endif