Coalesce warnings for deprecated lifecycle hooks and print single message after reconciliation (rather than one per component-type).

Relates to PR #12028 and [this comment](https://github.com/facebook/react/pull/12028#discussion_r162420575).
) {
            // 
            highestPriorityWork = remainingExpirationTime;
            highestPriorityRoot = root;
          }
          if (root === lastScheduledRoot) {
            break;
          }
          previousScheduledRoot = root;
          root = root.nextScheduledRoot;
        }
      }
    }
    // 
    // 
    const previousFlushedRoot = nextFlushedRoot;
    if (
      previousFlushedRoot !== null &&
      previousFlushedRoot === highestPriorityRoot
    ) {
      nestedUpdateCount++;
    } else {
      // 
      nestedUpdateCount = 0;
    }
    nextFlushedRoot = highestPriorityRoot;
    nextFlushedExpirationTime = highestPriorityWork;
  }
  function performAsyncWork(dl) {
    performWork(NoWork, dl);