Assumption that greentea test file is always named main.cpp is
incorrect. Updated mbed_greentea_add_test() macro to make TEST_SOURCES
parameter compulsory, which is used to specify greentea test
file(s). This allows tests to use C, or have a different name.
Therefore also updated all pre-existing greentea test CMake files to
explicity add main.cpp to TEST_SOURCES.
Adding mbed-os subdirectories that are not required for a specific project to .mbedignore is a good way to reduce compilation time. Sometimes it happens that tests depend on ignored files, which causes the test-build to fail even though the corresponding feature/component
is not configured. The reason is that the conditional that skips the test is placed after the includes.
Lingkai Dong
Hari Limaye
Sebastian Stockhammer
Rajkumar Kanagaraj
Hugues Kamba