Mark functions as not having CFI once we finalize an x86 stack frame

We'll set it back to true in emitPrologue if it gets called. It doesn't
get called for naked functions.

Fixes PR32912

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302092 91177308-0d34-0410-b5e6-96231b3b80d8

Author: rnk

lib/Target/X86/X86FrameLowering.cpp

@@ -2952,6 +2952,10 @@ unsigned X86FrameLowering::getWinEHParentFrameOffset(const MachineFunction &MF)
 
 void X86FrameLowering::processFunctionBeforeFrameFinalized(
     MachineFunction &MF, RegScavenger *RS) const {
+  // Mark the function as not having WinCFI. We will set it back to true in
+  // emitPrologue if it gets called and emits CFI.
+  MF.setHasWinCFI(false);
+
   // If this function isn't doing Win64-style C++ EH, we don't need to do
   // anything.
   const Function *Fn = MF.getFunction();

test/CodeGen/X86/win64_eh_leaf.ll

@@ -29,3 +29,12 @@ entry:
 ; and no unwind info in the object file.
 ; READOBJ-NOT: leaf_func
 }
+
+define void @naked_func() naked {
+  call void asm sideeffect "ret", ""()
+  unreachable
+}
+; ASM-LABEL: naked_func:
+; ASM-NOT: .seh_
+; ASM: ret
+; ASM-NOT: .seh_