cmake GME_HAS_DISABLE_ECHO examples

WohlSoft/SDL-Mixer-X src/codecs/music_gme.cmake :30

try_compile(GME_HAS_DISABLE_ECHO
                ${CMAKE_BINARY_DIR}/compile_tests
                ${SDLMixerX_SOURCE_DIR}/cmake/tests/gme_has_gme_disable_echo.c
                LINK_LIBRARIES ${GME_LIBRARIES} ${STDCPP_LIBRARY} ${M_LIBRARY}
                CMAKE_FLAGS "-DINCLUDE_DIRECTORIES=${GME_INCLUDE_DIRS}"
                OUTPUT_VARIABLE GME_TEST_RESULT
            )

WohlSoft/SDL-Mixer-X src/codecs/music_gme.cmake :37

message("gme_disable_echo() compile test result: ${GME_HAS_DISABLE_ECHO}")