Implement `ANDR` instruction

[craigthomas]

Implement the ANDR 6309 instruction mnemonic in the assembler. Performs a logical AND with a source and destination register, storing the result in the destination register.

Immediate - $1034, 4 bytes

Register codes:

D - 0000
X - 0001
Y - 0010
U - 0011
S - 0100
PC - 0101
W - 0110
V - 0111
A - 1000
B - 1001
CC - 1010
DP - 1011
E - 1110
F - 1111

Example:

ANDR A,B