### Website or app

https://codesandbox.io/s/react-playground-forked-j4niq

### Repro steps

Emoji seem supported but produce strange symbole

![image](https://user-images.githubusercontent.com/24865815/133793744-55a55582-90ad-425f-8a40-4c061a3c1d80.png)

To test emoji on Window Os, use `[win]+[.]` 🟩


### How often does this bug happen?

Every time

### DevTools package (automated)

_No response_

### DevTools version (automated)

_No response_

### Error message (automated)

_No response_

### Error call stack (automated)

_No response_

### Error component stack (automated)

_No response_

### GitHub query string (automated)

_No response_
b
      if (
        alternate == null ||
        treeBaseDuration !== alternate.treeBaseDuration
      ) {
         T
         S
        const convertedTreeBaseDuration = Math.floor(
          (treeBaseDuration || 0) * 1000,
        );
        pushOperation(TREE_OPERATION_UPDATE_TREE_BASE_DURATION);
        pushOperation(id);
        pushOperation(convertedTreeBaseDuration);
      }
      if (alternate == null || didFiberRender(alternate, fiber)) {
        if (actualDuration != null) {
           T
           T
           T
           S
           N
           T
          let selfDuration = actualDuration;
          let child = fiber.child;
          while (child !== null) {
            selfDuration -= child.actualDuration || 0;
            child = child.sibling;
          }
           I
           N