[XRay] Support AArch64 in LLVM

This patch adds XRay support in LLVM for AArch64 targets.
This patch is one of a series:

Clang: https://reviews.llvm.org/D26415
compiler-rt: https://reviews.llvm.org/D26413

Author: rSerge

Reviewers: rengolin, dberris

Subscribers: amehsan, aemerson, llvm-commits, iid_iunknown

Differential Revision: https://reviews.llvm.org/D26412

llvm-svn: 287209
diff --git a/llvm/lib/CodeGen/XRayInstrumentation.cpp b/llvm/lib/CodeGen/XRayInstrumentation.cpp
index e76bf69..1a74559 100644
--- a/llvm/lib/CodeGen/XRayInstrumentation.cpp
+++ b/llvm/lib/CodeGen/XRayInstrumentation.cpp
@@ -148,6 +148,7 @@
   switch (MF.getTarget().getTargetTriple().getArch()) {
   case Triple::ArchType::arm:
   case Triple::ArchType::thumb:
+  case Triple::ArchType::aarch64:
     // For the architectures which don't have a single return instruction
     prependRetWithPatchableExit(MF, TII);
     break;