Support inlay hints

[Kingwl]

Search Terms

editor, lsp, parameterHints

Suggestion

VSCode has supported decorators what could be implementation as label before some node.
We need to provide some text span to let vscode know .

Use Cases

Examples

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

[Kingwl]

I'd like to work on this both of ts and vscode If i may.

[Kingwl]

microsoft/vscode#113276

[Kingwl]

I think it would also fix #41297