Consolidate some note diagnostics

These note diags have the same message and can be unified further but for now
let's just bring them together.

Incidental change: Display a source range in the final attr diagnostic.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@209728 91177308-0d34-0410-b5e6-96231b3b80d8
Test requires exceptions

It's still XFAIL, but slightly closer to passing.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@209729 91177308-0d34-0410-b5e6-96231b3b80d8
Add a PR reference for XFAILed test

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@209730 91177308-0d34-0410-b5e6-96231b3b80d8