Convert the expression trait evaluation to a static function and
a switch with any default case. This both warns when an enumerator is
missing and asserts if a value sneaks through despite the warning.

While in there fix a bunch of coding style issues with this code.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@130648 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed