Display inherited JSDoc documentation in quick info

[ahejlsberg]

In this PR:

• Display inherited JSDoc documentation in quick info.
• Display JSDoc for actual signature when hovering over an overload or implementation signature.
• Consistently display constructor signature when hovering over new SomeClass(...) expression.

Fixes #2035.

[Copilot]

Pull Request Overview

This PR enhances the TypeScript language server's quick info feature by adding JSDoc documentation inheritance, showing specific overload signatures on hover, and consistently displaying constructor signatures for new expressions.

• Adds JSDoc inheritance from base classes/interfaces when derived members lack documentation
• Shows only the specific function/method overload being hovered over, rather than all overloads
• Displays constructor signatures when hovering over new ClassName() expressions

Reviewed Changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

File	Description
internal/ls/hover.go	Implements core logic for JSDoc inheritance, overload-specific display, and constructor signature handling
internal/checker/exports.go	Exports GetBaseTypes method needed for inheritance chain traversal
internal/fourslash/tests/gen/quickInfoForOverloadOnConst1_test.go	Updates test expectations to match new overload-specific display behavior
testdata/baselines/reference/fourslash/quickInfo/*.baseline	Updates baseline test outputs reflecting new JSDoc inheritance, overload display, and constructor signature features

[Copilot]

The condition getCallOrNewExpression(node) != nil matches both call and new expressions, but construct signatures should only be retrieved for new expressions. When hovering over a class name in a call expression context (e.g., MyClass()), this code would incorrectly attempt to get construct signatures. Consider checking specifically for new expressions using ast.IsNewExpression(callOrNewExpr) to ensure construct signatures are only shown in the appropriate context.

Suggested change

	if flags&ast.SymbolFlagsClass != 0 && getCallOrNewExpression(node) != nil {
	signatures = getSignaturesAtLocation(c, symbol, checker.SignatureKindConstruct, node)
	if flags&ast.SymbolFlagsClass != 0 {
	callOrNewExpr := getCallOrNewExpression(node)
	if callOrNewExpr != nil && ast.IsNewExpression(callOrNewExpr) {
	signatures = getSignaturesAtLocation(c, symbol, checker.SignatureKindConstruct, node)
	}