Add preprocessor guards to the definitions of size_t and wchar_t, and #undef NULL before defining it.
This addresses potential issues with system headers reported in <rdar://problem/7727159>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@98006 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed