[AArch64] Fix merge-store.ll regression test after r273271
[AArch64] Fix merge-store.ll regression test after r273271

r273271 changed the RUN line of the regression test to use
-march=cyclone instead of -mtriple=aarch64-none-none.

This caused a change in the output syntax for the ext
instruction, causing the test to fail. Change this test
back to using -mtriple=aarch64-none-none.



git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@273286 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm