Revert r195176, it is breaking buildbots for unclear reason


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195184 91177308-0d34-0410-b5e6-96231b3b80d8
Ensuring the warning for attribute decl types matches the error for attribute decl types.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195186 91177308-0d34-0410-b5e6-96231b3b80d8
Comment parsing tests: introduce a little more structure in testcase


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195187 91177308-0d34-0410-b5e6-96231b3b80d8
Removing a custom error diagnostic and replacing it with a stock one. Added a test case to ensure the diagnostic was firing properly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195188 91177308-0d34-0410-b5e6-96231b3b80d8