Add info and script on patching sysmodules manually

Source/Atmosphere/stratosphere/loader/source/oc/Makefile

@@ -3,7 +3,7 @@ export CC := g++-11
 all: test
 
 test:
-	$(CC) ldr_oc_suite.cpp test.cpp -o ./test -O2 -std=c++20
+	$(CC) ldr_oc_suite.cpp test.cpp -o ./test -O2 -std=c++20 -Wall
 
 clean:
 	rm ./test