Streamline arc-annotation test (removing some cases which do not add any extra coverage) and set it up to use FileCheck variables to make the test more robust.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179745 91177308-0d34-0410-b5e6-96231b3b80d8
Removed trailing whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179746 91177308-0d34-0410-b5e6-96231b3b80d8