Block building Tests in wrong command prompt (#4717)

Co-authored-by: Stephan T. Lavavej <[email protected]>

Author: fsb4000

Diff for: tests/utils/stl-lit/stl-lit.in

@@ -29,6 +29,13 @@ sys.path.insert(0, os.path.join("@LLVM_SOURCE_DIR@", 'utils', 'lit'))
 builtin_parameters= {}
 builtin_parameters['config_map'] = config_map
 
+def assert_same_platform_for_build_and_test():
+    build_platform = '$ENV{Platform}'
+    test_platform = os.getenv('Platform', default='')
+    if build_platform != '' and test_platform != '' and build_platform != test_platform:
+        exit(f'Target platform mismatch: the STL was built for {build_platform} but tested for {test_platform}.')
+
 if __name__=='__main__':
+    assert_same_platform_for_build_and_test()
     from lit.main import main
     main(builtin_parameters)