Emit -Wformat properly for bit-field promotions.

Only explicitly look through integer and floating-point promotion where the result type is actually a promotion, which is not always the case for bit-fields in C.

Patch by Bevin Hansson.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@349497 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed