LibTest: Expand test result bool to a TestResult

This will be used in the randomized tests a lot more than it is in the
unit tests / benchmarks; randomized tests will run the test function
multiple times, check the result and optionally start shrinking the
failing input. Generators will also be able to fail, resulting in some
of the new TestResult variants.

Userland/Libraries/LibTest/TestResult.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2023, Martin Janiczek <martin@janiczek.cz>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+namespace Test {
+
+// TestResult signals to the TestSuite how the TestCase execution went.
+enum class TestResult {
+    NotRun,
+
+    // Test fn ran to completion without setting any of the below flags
+    Passed,
+
+    // Didn't get through EXPECT(...).
+    Failed,
+};
+
+// Used eg. to signal we've ran out of prerecorded random bits.
+// Defined in TestSuite.cpp
+void set_current_test_result(TestResult);
+
+} // namespace Test