Test comments indicated that having rkwl_wdc_op set to > 1 means
no test, but there was conditional that was just checking
that the value was not 0 and thereby causing those opcodes
to be tests when this value was set to > 1
self modifying immediate opcodes now execute in data RAM. the remaining
self modifying branch range test is supplemented by an early pretest to
check for correct relative addressing.
Some emulators employ separate opcode table to switch between binary and
decimal arithmetic. The added test verifies proper binary or decimal
operation after CLD, SED, PLP & RTI.
