PC in superH should be 4 bytes ahead of current instruction

[Z-Gu]

According to bottom of pg14 of the attached manual, PC of sh7700 series "indicates starting address of the current instruction incremented by 4"
DSA-338480.pdf

[phillipstanleymarbell]

This is already handled in superH_bf () (please see the 20-line block starting at https://github.com/phillipstanleymarbell/sunflower-simulator/blob/81afa791d8abb311312dd4563d5b9780026ce490/sim/op-hitachi-sh.c#L523).