This is a change in behavior from CMake 3.3, but there is no semantic meaning
to empty entries in buildsystem properties. This also restores behavior to
that of CMake 2.8.10.
Extend the RunCMake.set_property test with cases covering buildsystem
target properties:
* COMPILE_DEFINITIONS
* COMPILE_FEATURES
* COMPILE_OPTIONS
* INCLUDE_DIRECTORIES
* LINK_LIBRARIES
* SOURCES
Also test a non-buildsystem property to document the current difference
in behavior. Refactor the existing LINK_LIBRARIES case to the same
more-extensive test as the rest. Use the output generated by CMake 3.3
as the expected output for each test case.
Stephen Kelly
Brad King