Bunch of warning fixes

tests/ExtraTests/X02-DisabledMacros.cpp

@@ -16,11 +16,25 @@ struct foo {
     }
 };
 
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wglobal-constructors"
+#endif
 // Construct foo, but `foo::print` should not be run
 foo f;
 
+
+#if defined(__clang__)
+// The test is unused since the registration is disabled
+#pragma clang diagnostic ignored "-Wunused-function"
+#endif
+
 // This test should not be run, because it won't be registered
 TEST_CASE( "Disabled Macros" ) {
     std::cout << "This should not happen\n";
     FAIL();
 }
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif