Ensure that cmStandardIncludes.h is included before any platform header
in cmGeneratorExpressionEvaluator.h. That file needs to change as
a result of removal of the cmMakefile.h header from
cmGeneratorExpressionNode.h, affecting the compilation of
cmGeneratorExpressionNode.cxx.
On AIX we need to include our own headers first to get large file
support macros defined consistently within system headers. The old
order in this header worked only because it was always included after
other headers.
The expressions may be parsed and then cached and evaluated multiple
times. They are evaluated lazily so that literals such as ',' can be
treated as universal parameter separators, and can be processed from
results without appearing literally, and without interfering with the
parsing/evaluation of the entire expression.
Stephen Kelly