feat: preserve class names when renaming declarations

[Demivan]

Description

Preserve class names when fixing naming collisions.

When variable name clashes:

const a = class {}

becomes:

const a$1 = class a {}

When class name clashes:

class A {}

becomes:

var A$1 = class A {} 

Test Plan

Enabled rollup@function@class-name-conflict test.

This is my first actual Rust PR, so there could be issues.

---

[netlify]

✅ Deploy Preview for rolldown-rs canceled.

Name	Link
🔨 Latest commit	dbf0615
🔍 Latest deploy log	https://app.netlify.com/sites/rolldown-rs/deploys/65ec8548d2605e0008aec3d5

[netlify]

✅ Deploy Preview for rolldown-rs canceled.

Name	Link
🔨 Latest commit	cc03db0
🔍 Latest deploy log	https://app.netlify.com/sites/rolldown-rs/deploys/65ec85575faafc00087537b6

[hyf0]

Thank for your contribution.

Yes, this is an important behavior and we plan to follow the esbuild's behavior and support both function and class. It's not an easy task, since we need to integrate the feature with tree shaking and expose options to users. We don't want simply add this behavior so far.

[Demivan]

Makes sense. I tried to match the Rollup implementation instead.

I will create a separate pr with c5e1779 - adds more info about failure in Rollup tests.

What can be worked on then?

[hyf0]

Makes sense. I tried to match the Rollup implementation instead.

I will create a separate pr with c5e1779 - adds more info about failure in Rollup tests.

What can be worked on then?

Glad you are interested in it. Just create a good first issue: #511