Initialize aarch64-cond-br-tuning pass (llvm#132087)

The call to the initializeAArch64CondBrTuningPass function is missing in
the AArch64TargetMachine LLVMInitializeAArch64Target function.

This means that the pass is not in the pass registry and options such as
-run-pass=aarch64-cond-br-tuning and
-stop-after=aarch64-cond-br-tuning cannot be used. This patch fixes that
issue.

(cherry picked from commit cc86d7c)

Author: rastogishubham

llvm/lib/Target/AArch64/AArch64TargetMachine.cpp

@@ -264,6 +264,7 @@ extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAArch64Target() {
   initializeAArch64LowerHomogeneousPrologEpilogPass(*PR);
   initializeAArch64DAGToDAGISelLegacyPass(*PR);
   initializeAArch64GlobalsTaggingPass(*PR);
+  initializeAArch64CondBrTuningPass(*PR);
 }
 
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