message: Fix disassembly of SPIR-V subtract operations
diff: @@ -66,7 +66,7 @@ static rdcstr StringiseBinaryOperation(const std::function<rdcstr(rdcspv::Id)> &
  case rdcspv::Op::IAdd:
  case rdcspv::Op::FAdd: ret += "+"; break;
  case rdcspv::Op::ISub:
  - case rdcspv::Op::FSub: ret += "+"; break;
  + case rdcspv::Op::FSub: ret += "-"; break;
  case rdcspv::Op::IMul:
  case rdcspv::Op::FMul:
  case rdcspv::Op::VectorTimesMatrix:
  