Format string analysis: give 'q' its own enumerator.

This is in preparation for being able to warn about 'q' and other
non-standard format string features.

It also allows us to print its name correctly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150697 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed