Move tests from projects/ to tests/

tests/ExtraTests/X11-DisableStringification.cpp

@@ -0,0 +1,16 @@
+// X11-DisableStringification.cpp
+// Test that stringification of original expression can be disabled
+// this is a workaround for VS 2017 issue with Raw String literal
+// and preprocessor token pasting. In other words, hopefully this test
+// will be deleted soon :-)
+
+#define CATCH_CONFIG_MAIN
+#include <catch2/catch.hpp>
+
+struct Hidden {};
+
+bool operator==(Hidden, Hidden) { return true; }
+
+TEST_CASE("DisableStringification") {
+    REQUIRE( Hidden{} == Hidden{} );
+}