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.
Provides header files that use preprocessor tests to detect and provide
information about the compiler and its target architecture. The headers
contain no configuration-time test results and thus may be installed
into an architecture-independent include directory. This makes them
suitable for use in the public interface of any package.