The test needed some updates to run using a different UI toolkit and with a different libMTC, but it should run fine on a device. llvm-svn: 374262
This adds a simple testcase for MainThreadCheckerRuntime. The tool (Main Thread Checker) is only available on Darwin, so the test also detects the presence of libMainThreadChecker.dylib and is skipped if the tool is not available. llvm-svn: 307170