Style nit. Dereference `&SymbolId` to `SymbolId` as early as possible. `&SymbolId` is 8 bytes, whereas `SymbolId` is 4 bytes.
In simple cases like these, compiler will optimize it anyway, but still I think it's a better pattern to dererence early. In more complicated cases, it will be better for performance, and in my opinion, it makes things clearer if vars called `symbol_id` are always a `SymbolId`, and not sometimes a `&SymbolId`.
Realized we can get the source type from the AST.
The next PR will introduce `unambiguous` to `SourceType` and directly set `Program::source_type` to either `script` or `module`.
Make `ScopeId` a type with a niche, like `SymbolId` and `ReferenceId`. This makes `Option<ScopeId>` 4 bytes instead of 8, and shrinks various AST types e.g. `ArrowFunctionExpression` by 8 bytes, and halves the size of the `Vec` in `ScopeTree::parent_ids`.
The snapshot change on `prefer-hooks-in-order` lint rule appears incidental - it doesn't alter what errors are reported, only the order they're reported in. This appears to be because it changes the order of keys in a hashmap keyed by `ScopeId` that [the rule uses](a49f4915de/crates/oxc_linter/src/rules/jest/prefer_hooks_in_order.rs (L143)).
