When SimplifyCFG merges identical instructions from both sides of a diamond, it
can preserve !llvm.mem.parallel_loop_access (as it does with most of the other
metadata). There's no real data or control dependency change in this case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267515 91177308-0d34-0410-b5e6-96231b3b80d8
