message: add memory utilization estimate for HLO op profile.
diff: @@ -60,6 +60,11 @@ message Metrics {
  // - it does not reveal the peak core FLOPS of the hardware
  double flops = 2;
  + // The VMEM bandwidth used to load operands from HBM, as a fraction of
  + // thereotical VMEM bandwidth on the specific hardware.
  + double memory_bandwidth = 3;
  +
  double raw_time = 11; // Elapsed core-time in picoseconds.
  double raw_flops = 12; // Total floating-point operations performed.
  + double raw_bytes_accessed = 13; // Total bytes accessed (include read/write).
  }
  