Implement BITD instruction

[craigthomas]

Implement the BITD 6309 instruction mnemonic in the assembler. Performs a logical AND between D and a memory value, however, the value is not stored. Sets the condition code register accordingly.

Immediate - $1085, 4 bytes
Direct - $1095, 3 bytes
Indexed - $10A5, 3+ bytes
Extended - $10B5, 4 bytes

Example:

BITD #$0800

Note that overflow V is always 0, and only the negative N and zero Z flags are modified.