[PECOFF] Ignore /verbose and /wx (warnings as errors) options.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@191317 91177308-0d34-0410-b5e6-96231b3b80d8
[PECOFF] Fix /? option and add a test for the flag.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@191320 91177308-0d34-0410-b5e6-96231b3b80d8