Set Size appropriately in operand definitions and query it for dumping memory
operand size table getMemOperandSize (follow-up use D126116) and
X86Disassembler::getMemOperandSize.
Excerpt from a produced getMemOperandSize table for X86:
static int getMemOperandSize(int OpType) {
  switch (OpType) {
  default: return 0;
  case OpTypes::i8mem:
  case OpTypes::i8mem_NOREX:
    return 8;
  case OpTypes::f16mem:
  case OpTypes::i16mem:
    return 16;
  case OpTypes::f32mem:
  case OpTypes::i32mem:
    return 32;
...
Could you also simply the function getMemOperandSize in X86RecognizableInstr.cpp in this patch? You can return value of Size now.