Compiler warnings can be fixed by using h instead of j in case RETURN_VALUE & casting CONST_LEN() to unsigned is safe

As for the failing tests: I've finally figured out how to use Tools/freeze to fix __phello__ et al. I've brought up the trace test failure a few times, essentially

return (1,
2,
3)

compiles to LOAD_CONST (1,2,3) being on separate line than the RETURN_VALUE whereas previously it did not. This issue does not occur for

return """1,
2,
3"""

Leading me to believe peephole has missed some detail in ltotab handling