[llvm] x86: fix musttail sibcall miscompilation (PR #168956)

[Folkert de Vries via llvm-commits]

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@@ -2684,102 +2914,6 @@ X86TargetLowering::GetAlignedArgumentStackSize(const unsigned StackSize,
   return alignTo(StackSize + SlotSize, StackAlignment) - SlotSize;
 }
 
-/// Return true if the given stack call argument is already available in the
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folkertdev wrote:

this function got moved up so it can be used.

https://github.com/llvm/llvm-project/pull/168956