[XRay][AArch64] An attempt to fix test patching-unpatching.cc by flushing the instruction cache after code modification
Summary: This patch attempts to fix test patching-unpatching.cc . The new code flushes the instruction cache after modifying the program at runtime.
Reviewers: dberris, rengolin, pelikan, rovka
Subscribers: rovka, llvm-commits, iid_iunknown, aemerson
Differential Revision: https://reviews.llvm.org/D27996