Remove ScanfArgType and bake that logic into ArgType.

This is useful for example for %n in printf, which expects
a pointer to int with the same logic for checking as %d
would have in scanf.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161407 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed