Add __INTMAX_C_SUFFIX__ and __UINTMAX_C_SUFFIX__.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213097 91177308-0d34-0410-b5e6-96231b3b80d8
Switching some iterator-based for loops to use range-based for loops. No functional changes intended.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213098 91177308-0d34-0410-b5e6-96231b3b80d8