tests: add all platform tests and skip needed tests

Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>

run_tests.py

@@ -201,12 +201,9 @@ def detect_tests_to_run():
     all_tests.append(('failing', gather_tests('test cases/failing'), False))
     all_tests.append(('prebuilt object', gather_tests('test cases/prebuilt object'), False))
 
-    if mesonlib.is_osx():
-        all_tests.append(('platform', gather_tests('test cases/osx'), False))
-    elif mesonlib.is_windows():
-        all_tests.append(('platform', gather_tests('test cases/windows'), False))
-    else:
-        all_tests.append(('platform', gather_tests('test cases/linuxlike'), False))
+    all_tests.append(('platform-osx', gather_tests('test cases/osx'), False if mesonlib.is_osx() else True))
+    all_tests.append(('platform-windows', gather_tests('test cases/windows'), False if mesonlib.is_windows() else True))
+    all_tests.append(('platform-linux', gather_tests('test cases/linuxlike'), False if not (mesonlib.is_osx() or mesonlib.is_windows()) else True))
     all_tests.append(('framework', gather_tests('test cases/frameworks'), False if not mesonlib.is_osx() and not mesonlib.is_windows() else True))
     all_tests.append(('java', gather_tests('test cases/java'), False if not mesonlib.is_osx() and shutil.which('javac') else True))
     all_tests.append(('C#', gather_tests('test cases/csharp'), False if shutil.which('mcs') else True))