[llvm] [BOLT][BTI] Refactor: move applyBTIFixup under MCPlusBuilder (PR #177164)

[Paschalis Mpeis via llvm-commits]

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@@ -43,6 +43,8 @@ static void relaxStubToShortJmp(BinaryBasicBlock &StubBB, const MCSymbol *Tgt) {
   BC.MIB->createShortJmp(Seq, Tgt, BC.Ctx.get());
   StubBB.clear();
   StubBB.addInstructions(Seq.begin(), Seq.end());
+  if (BC.usesBTI())
+    BC.MIB->applyBTIFixupToTarget(StubBB);
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paschalis-mpeis wrote:

Do you think we could move these into MIB's `createShortJmp` and `createLongJmp`, respectively?

https://github.com/llvm/llvm-project/pull/177164