[AVR] Added machine code support for CP and CPC instructions
[AVR] Removed relative jump target address check
[AVR] Extended FSTDPqRr to be more generic
[AVR] Added machine code support for LDD
[AVR] Made AVR_SUPPORT.md aware of the variations of LD/ST
[AVR] Added machine code implementations for LD/ST
[AVR] Refactored FSTLDPtrReg to be more generic
[AVR] Implemented machine code generation for store/load
instructions