Web Inspector: objects can have multiple private fields with the same name

[Devin Rousso]

# STEPS TO REPRODUCE
1. inspect any page
2. log the following in the Console
```
class Foo { #foo = 42; static #bar = 42; #baz() { } }
class Bar extends Foo { #foo = 'asd'; static #bar = 'asd'; #baz() { } }
new Bar
```

## EXPECTED
Bar {#foo: 42, #foo: "asd"}

## ACTUAL
Bar {#foo: "asd"}

[Devin Rousso]

Pull request: https://github.com/WebKit/WebKit/pull/13448

[Radar WebKit Bug Importer]

<rdar://problem/109215331>

[EWS]

Committed 267483@main (eba01be516e6): <https://commits.webkit.org/267483@main>

Reviewed commits have been landed. Closing PR #13448 and removing active labels.