[llvm] [ARM] Fix -mno-omit-leaf-frame-pointer flag doesn't works on 32-bit ARM (PR #109628)

[via llvm-commits]

================
@@ -40,6 +40,20 @@ bool TargetOptions::DisableFramePointerElim(const MachineFunction &MF) const {
   llvm_unreachable("unknown frame pointer flag");
 }
 
+/// DisableLeafFramePointerElim - This returns true if leaf frame pointer
+/// elimination optimization should be disabled for the given machine function.
+bool TargetOptions::DisableLeafFramePointerElim(
----------------
guoxin049 wrote:

I did an experiment and changed it like this `bool CanEliminateFrame = !(requiresAAPCSFrameRecord(MF) && hasFP(MF)) && !MF.getTarget().Options.DisableFramePointerElim(MF);`
However, fp is retained in the following scenarios:
https://github.com/llvm/llvm-project/blob/3f37c517fbc40531571f8b9f951a8610b4789cd6/llvm/lib/Target/ARM/ARMFrameLowering.cpp#L180-L185
I don't know if it makes sense. For example, the fast-isel-intrinsic.ll test case saves fp.


https://github.com/llvm/llvm-project/pull/109628