Teach KWIML_test to use part of the C++ runtime library. Otherwise the
linker complains:
warning LNK4089: all references to 'MSVCP71.dll' discarded by /OPT:REF
Some system headers may define macros that interfere with preprocessor
tests in KWIML headers. Test this case to be sure that the verification
checks at the bottom of the headers do not fail.