[llvm] [X86] Support EGPR (R16-R31) for APX (PR #67702)

[Shengchen Kan via llvm-commits]

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@@ -37,6 +37,7 @@ define void @f_thunk(ptr %this, ...) {
 ; LINUX-NEXT:    .cfi_offset %r14, -32
 ; LINUX-NEXT:    .cfi_offset %r15, -24
 ; LINUX-NEXT:    .cfi_offset %rbp, -16
+; LINUX-NEXT:    movb %al, {{[-0-9]+}}(%r{{[sb]}}p) # 1-byte Spill
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KanRobert wrote:

Explained in description.

https://github.com/llvm/llvm-project/pull/67702