'decodeURIComponent' fails to throw URIError for invalid UTF-8 sequences

### Description

When decoding the invalid UTF-8 sequence `%ED%BF%BF`, `decodeURIComponent` outputs replacement characters `���` instead of throwing a `URIError`, violating ECMA-262 specifications.

### Version

```
a29e8f5
```

### Testcase

```
print(decodeURIComponent('%ED%BF%BF'));
```

### Output

```
���
```

### Expected output

```
Throw 'URIError'
```

