MSVC supports only C89, so it is important to keep c-index-test.c
buildable with C89.  However, Clang defaults to C99, so while building
Clang with Clang one can introduce C99 constructs into c-index-test.c
without noticing.

Thanks to Nakamura Takumi for helping with MSVC bits.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167561 91177308-0d34-0410-b5e6-96231b3b80d8