FORCE_REX         887 lj_asm_x86.h         op = XO_MOVSXb; allow = RSET_GPR8; dest |= FORCE_REX;
FORCE_REX         889 lj_asm_x86.h         op = XO_MOVZXb; allow = RSET_GPR8; dest |= FORCE_REX;
FORCE_REX        1450 lj_asm_x86.h       case IRT_I8: case IRT_U8: xo = XO_MOVtob; src |= FORCE_REX; break;
FORCE_REX        2508 lj_asm_x86.h   		left |= FORCE_REX;
FORCE_REX          15 lj_emit_x86.h  #define REX_64			(FORCE_REX|0x080000)
FORCE_REX          59 lj_emit_x86.h      uint32_t rex = 0x40 + ((rr>>1)&(4+(FORCE_REX>>1)))+((rx>>2)&2)+((rb>>3)&1);