[test/CodeGen/ARM] Update arm_neon_intrinsics test case to actually test the
lowering of the intrinsics.
Prior to this commit, most of the copy-related intrinsics could be optimized
away. The situation is still not ideal as there are several possibilities to
lower a given intrinsic. Currently, we match LLVM behavior.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216474 91177308-0d34-0410-b5e6-96231b3b80d8