message: Add useful params for PMLSim
diff: @@ -19,6 +19,7 @@ message Config {
  repeated Bus buses = 6;
  repeated Pass passes = 7;
  repeated Pass lowering = 8;
  + optional uint32 i8_mac_ops_per_cycle = 9;
  }
  // An execution unit represents a simulated computing device.
  @@ -32,6 +33,7 @@ message ExecutionUnit {
  message MemoryUnit {
  optional uint32 count = 1 [default = 1];
  required uint32 size_KiB = 2;
  + optional bool is_host = 3 [default = false];
  }
  // A transfer unit represents a processing element that moves memory between
  