Previously we expanded HAVE_FINAL to determine what the copied_file number
would be, but when we don't have cxx_final than HAVE_FINAL is not defined.
What we really want is to use expected_result.
Allow setting build properties based on the features available
for a target. The availability of features is determined at
generate-time by evaluating the link implementation.
Ensure that the <LANG>_STANDARD determined while evaluating
COMPILE_FEATURES in the link implementation is not lower than that
provided by the INTERFACE of the link implementation. This is
similar to handling of transitive properties such as
POSITION_INDEPENDENT_CODE.
Robert Maynard
Stephen Kelly