Get cpu6502 to pass functional tests from https://github.com/Klaus2m5/6502_65C02_functional_tests
Set bit 5 on status register pushed during IRQ, NMI, BRK.
Fix return address pushed for BRK
Fix flag setting for ROR
Fix flags pushed with PHP
Fix return address for RTI
Add 0xD5 - DEC zpg, X
Add 0xE1 - SBC (ind, X)
Add 0x61 - ADC (ind, X)
Add 0x1E - ASL abs, x
Add 0x21 - AND (ind, X)
Add 0x96 - STX zpg, Y
add 0x75 - ADC zpg, X
