Check branch instructions for automated optimizations

[craigthomas]

In certain circumstances, a user may issue an instruction such as:

LBCC FUNCTION

This instructs the CPU to perform a long branch to where FUNCTION is located in memory. Long branches are useful since they can be used to branch to anywhere in the 64K memory space. However, if FUNCTION is within +129 bytes or -126 bytes of the current instruction, then we can transform the LBCC to a BCC instead, saving several op-cycles, as well as a byte in instruction op-codes.