[clang] [llvm] [ARM] Add support for Windows SEH (PR #184953)

[Trung Nguyen via cfe-commits]

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@@ -1110,6 +1123,7 @@ void ARMFrameLowering::emitPrologue(MachineFunction &MF,
     DefCFAOffsetCandidates.addInst(LastPush, GPRCS3Size, BeforeFPPush);
     if (FramePtrSpillArea == SpillArea::GPRCS3)
       BeforeFPPush = false;
+    NumBytes -= GPRCS3Size;
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trungnt2910 wrote:

Resolved on [Discord](https://discord.com/channels/636084430946959380/745925509971705877/1487070054767005757).

> That represents the amount of stack to allocate, in this case divided by 4 - the number comes from here: https://github.com/llvm/llvm-project/blob/llvmorg-22.1.2/llvm/lib/Target/ARM/ARMFrameLowering.cpp#L1118-L1139
I.e. it allocates 4*1256=5024 bytes of stack space for the function

https://github.com/llvm/llvm-project/pull/184953