This diff addresses FIXME in lib/Analysis/PrintfFormatString.cpp
and makes PrintfSpecifier::getArgType return the correct type.
In particular, this change enables Clang to emit a warning on
incorrect using of "%zd"/"%zn" format specifiers.
Differential revision: https://reviews.llvm.org/D35427
Test plan: make check-all
llvm-svn: 308067