GCC 14 seh_cfa_offset regression fix (#138)

Author: skeeto

src/gcc-seh_cfa_offset.patch

@@ -0,0 +1,19 @@
+commit 2f0e0862406a17bb8bf4ad948ae22916bae092a0
+Author: Eric Botcazou <[email protected]>
+Date:   Wed May 22 18:10:39 2024 +0200
+
+    Fix internal error in seh_cfa_offset with -O2 -fno-omit-frame-pointer
+
+    The problem directly comes from the -ffold-mem-offsets pass messing up with
+    the prologue and the frame-related instructions, which is a no-no with SEH,
+    so the fix simply disconnects the pass in these circumstances.
+
+    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115038
+
+--- a/gcc/fold-mem-offsets.cc
++++ b/gcc/fold-mem-offsets.cc
+@@ -493,3 +493,3 @@ fold_offsets (rtx_insn *insn, rtx reg, bool analyze, bitmap foldable_insns)
+ 
+-  if (!def || GET_CODE (PATTERN (def)) != SET)
++  if (!def || RTX_FRAME_RELATED_P (def) || GET_CODE (PATTERN (def)) != SET)
+     return 0;