[opt-viewer] Suppress noisy Swift remarks

Most likely, this is not how we want to handle this in the long term.  This
code should probably be in the Swift repo and somehow plugged into the
opt-viewer.  This is still however very experimental at this point so I don't
want to over-engineer it at this point.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319902 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed