Added many more core instructions
Added many more core instructions

* Added encodings and wrapper functions for many more core instructions, including: BT, BTS, BTR, BTC, CBW, CWDE, CDQE, CWD, CDQ, CQO, CLC, CMC, STC, CMPXCHG, CMPXCHG8B, CMPXCHG16B, CPUID, MOVSB, MOVSW, MOVSD, MOVSQ, REP_MOVSB, REP_MOVSW, REP_MOVSD, REP_MOVSQ, PAUSE, POPF, POPFQ, PUSHF, PUSHFQ, RDPMC, RDTSC, RET, STOSB, STOSW, STOSD, STOSQ, REP_STOSB, REP_STOSW, REP_STOSD, REP_STOSQ, UD2, XADD.
ndickson/encodeasm