Patch TestRunner for proper error code on exit.

io/tests/correctness/run.io

@@ -1,2 +1,34 @@
 #!/usr/bin/env io
-TestSuite clone setPath(System launchPath) run
+
+// patch TestRunner to upstream Io's version
+TestRunner run = method(testMap,
+    self cases := testMap # Storing a reference to the test map.
+    self runtime := Date secondsToRun(
+        testMap foreach(testCaseName, testSlotNames,
+            # Depending on the Lobby is kind of wacky, but that's
+            # all we can do, since Map only supports string keys.
+            testCase := Lobby getSlot(testCaseName)
+            testSlotNames foreach(name,
+                testCase setUp
+                exc := try(stopStatus(testCase doString(name)))
+                if(exc, error(testCaseName .. " " .. name, exc), success)
+                testCase tearDown
+            )
+        )
+    )
+
+    printExceptions
+    printSummary
+    self exceptions
+)
+
+if(System args size > 1,
+    # Run specific tests.
+    System args slice(1) foreach(name,
+        Lobby doFile(System launchPath .. "\\" ..  name)
+    )
+    System exit(FileCollector run size)
+,
+    # Run all tests in the current directory.
+    System exit(DirectoryCollector run size)
+)