Preserve class bindings in computed member names

[Copilot]

Legacy decorator emit replaced class references in direct computed member names with an alias that is not assigned until class evaluation completes.

@dec
class C {
    [C.name]() {}
}

Changes

• Preserve the class binding in direct computed member names.
• Retain alias substitution for deferred references, including nested classes inside methods.
• Cover methods, accessors, decorated static fields, and ES2020/ES2022 emit.

• Fixes Investigate decorator initialization order re: renames of classes #63758