message: Ruy: Output message when overriding block map size.
diff: @@ -331,13 +331,17 @@ void MakeBlockMap(int rows, int cols, int depth, int kernel_rows,
  fprintf(stderr, "best_score_block_size_log2=%d\n",
  best_score_block_size_log2);
  }
  - firsttime = false;
  static const char* explicit_block_size_log2_env =
  getenv("RUY_MAKEBLOCKMAP_EXPLICIT_BLOCK_SIZE_LOG2");
  if (explicit_block_size_log2_env) {
  best_score_block_size_log2 = std::stoi(explicit_block_size_log2_env);
  + if (firsttime || debug_everytime) {
  + fprintf(stderr, "Overridden best_score_block_size_log2=%d\n",
  + best_score_block_size_log2);
  }
  + }
  + firsttime = false;
  #endif
  int num_blocks_base_log2 = size_log2 - best_score_block_size_log2;
  