### 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_
Differentiates between a null context value and no context.
  const NO_CONTEXT = {};
  function getContextsForFiber(fiber: Fiber): [Object, any] | null {
    let legacyContext = NO_CONTEXT;
    let modernContext = NO_CONTEXT;
    switch (getElementTypeForFiber(fiber)) {
      case ElementTypeClass:
        const instance = fiber.stateNode;
        if (instance != null) {
          if (
            instance.constructor &&
            instance.constructor.contextType != null
          ) {
            modernContext = instance.context;
          } else {
            legacyContext = instance.context;
            if (legacyContext && Object.keys(legacyContext).length === 0) {
              legacyContext = NO_CONTEXT;
            }
          }
        }
        return [legacyContext, modernContext];
      case ElementTypeFunction:
        const dependencies = fiber.dependencies;
        if (dependencies && dependencies.firstContext) {
          modernContext = dependencies.firstContext;
        }
        return [legacyContext, modernContext];
      default:
        return null;