fix(rp2040): fix subs registers wrong overflow handling

[Turro75]

close #46

[urish]

Also, can you move the STR fix into a different pull request (different branch), together with the test case from #43?

I think a bunch of other instructions have the same issue as well: STRH, STRB, LDR, LDRB, LDRH, LDRS, LDRSB

We can skip creating tests for each one of them, but since we already have the test case for STR, let's at least include it

edit: pardon, I see you already included the test case for STR. I guess I'm too tired at this hour :)

[Turro75]

I'm gonna reworking it

[urish]

Thank you!