perf(semantic): use FxHashMap to replace IndexVec for symbol_redeclarations

[Dunqing]

Further improve on #4463.

As #4463 said:

Most symbols don't have redeclarations.

Yes, so inserting a None for every SymbolId is also unnecessary, changes to FxHashMap so that we can insert where redeclaration appears.

There is a 1% performance improvement in semantic!

[Dunqing]

• feat(semantic): add symbol_id for declare class binding #10095
• refactor(semantic): align handling of declaring symbol for class with TypeScript #10094
• feat(semantic): check redeclaration of function declaration and class declaration #10093
• feat(semantic): add symbol_id for declare function binding #10078
• refactor(semantic): align handling of declaring symbol for function with TypeScript #10086
• feat(semantic): check redeclaration of variable declaration and function declaration in the block scope #10074
• fix(semantic): define a variable in a function expression whose name is the same as the function name which is considered a redeclaration #10077
• refactor(semantic)!: store symbol information as the first entry in symbol_declarations when it is redeclared #10062
• feat(semantic/scoping): add declaration and flags fields for Redeclaraion #10060
• feat(semantic): introduce Redeclaraion for Scoping::symbol_declarations #10059
• perf(semantic): use FxHashMap to replace IndexVec for symbol_redeclarations #10058 👈 (View in Graphite)
• main

---

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• 0-merge - adds this PR to the back of the merge queue
• hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

This stack of pull requests is managed by Graphite. Learn more about stacking.

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #10058 will not alter performance

_{Comparing 03-25-refactor_semantic_use_fxhashmap_to_replace_indexvec_for_symbol_redeclarations (84e167e) with main (5e14fe9)}

Summary

✅ 33 untouched benchmarks

[graphite-app]

Merge activity

• Mar 28, 12:11 AM EDT: Boshen added this pull request to the Graphite merge queue.
• Mar 28, 12:18 AM EDT: A user merged this pull request with the Graphite merge queue.

[overlookmotel]

I'm late to the party on this one but: Nice!

I'm not sure why I used the IndexVec<SymbolId, Option<RedeclarationId>> in the first place. A hash map is much better, for the reasons you gave.