Fix decorator memoiser binding kind

[JLHwung]

Q	A
Fixed Issues?	Babel does not bind decorators correctly when the class is within a for loop (REPL)
Patch: Bug Fix?	Yes
Major: Breaking Change?
Minor: New Feature?
Tests Added + Pass?	Yes
Documentation PR Link
Any Dependency Changes?
License	MIT

This issue is very similar to https://github.com/babel/babel/pull/10029/files#r287785963. In the REPL example

{
  const logs = [];
  const classes = [];
  const setValueTo = i => () => () => i

  for (let i = 0; i < 2; i++) {
    classes.push(class C {
      @setValueTo(i) [i];
    })
  }

  for (const clazz of classes) {
    const c = new clazz();
    const key = Reflect.ownKeys(c)[0];
    logs.push([key, c[key]].join(":"));
  }

  console.log(logs.join())
}

It should print 0:0,1:1 while currently it prints 0:1,1:1.

To address this issue we have to register all decorator memoisers as let bindings. I suggest we also add a kind: "var" | "let" parameter to Scope#generateDeclaredUidIdentifier(name: string) so that in Babel 8 we can just switch to the official scope method.

As usual, please review this PR by commits. (I promise this PR has <100 commits :))

c.f. #16325 (comment)

[JLHwung]

This binding is generated by the class properties transform, so it is still var.

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/56478

[liuxingbaoyu]

Can you add this test?

[JLHwung]

Can you add this test?

Did you mean

babel/packages/babel-plugin-proposal-decorators/test/fixtures/2023-11-misc--to-es2015/class-in-for-loop/exec.js

Lines 55 to 73 in 8c456e3

	{
	const logs = [];
	const classes = [];
	const setValueTo = i => () => () => i
	for (let i = 0; i < 2; i++) {
	classes.push(class C {
	@setValueTo(i) [i];
	})
	}
	for (const clazz of classes) {
	const c = new clazz();
	const key = Reflect.ownKeys(c)[0];
	logs.push([key, c[key]].join(":"));
	}
	expect(logs.join()).toBe("0:0,1:1");
	}

?

[liuxingbaoyu]

Sorry missed it. Thanks!

[JLHwung]

For reviewers: new test cases are added to 2023-11-misc/class-in-for-loop/exec.js

[JLHwung]

@liuxingbaoyu Thanks for rebasing.