These are tests that fail in the next commit without this flag. This
does not add -verify-ignore-unrelated to all tests with -verify, only
the ones that would fail without it. This is NFC since this flag is
currently a no-op.
When onlyIfImported is true, we should return the public module name
only when the public facing module is already imported. Replace the
call to getModuleByIdentifier with getLoadedModule to prevent trigering
loading that module.
Also fix the test where the CHECK lined ended up matching itself from
the diagnostics output.
