fix: allow references to unexported types

[raimannma]

This PR fixes an issue where referencing unexported types indirectly (e.g., via Parameters<typeof fn>[1]) would fail during declaration emit.

The fix involves implementing tryReuseExistingTypeNodeHelper in the node builder. This allows the compiler to reuse the existing type node from the source code if the entity names within it are visible in the emitting scope, rather than attempting to synthesize a new type node from the resolved type (which would fail if the underlying type is unexported).

Fixes #2504

[raimannma]

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[Copilot]

Pull request overview

This PR fixes a declaration emit error (TS4023: "cannot be named") that occurred when using indirect type references to unexported types through utility types like Parameters<typeof fn>[1]. The fix implements the tryReuseExistingTypeNodeHelper function in the node builder to reuse existing type nodes from source code when all entity names within them are visible in the emitting scope, rather than attempting to synthesize new type nodes from resolved types (which would fail for unexported types).

Changes:

• Implements tryReuseExistingTypeNodeHelper to validate and reuse existing type nodes with visibility checks
• Adds new tracker methods (IsEntityNameVisible and TrackEntityName) to check entity name visibility
• Replaces getOptionalType calls with addOptionalityEx to properly handle optionality with strict mode awareness
• Adds a test case demonstrating the fix for the reported issue

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
testdata/tests/cases/conformance/parametersTypeResolutionWithUnexportedInterface.ts	Test case verifying the fix for indirect references to unexported types via Parameters utility type
internal/nodebuilder/types.go	Adds interface methods for entity name visibility checking
internal/checker/symboltracker.go	Implements entity name visibility forwarding methods in checker's symbol tracker
internal/transformers/declarations/tracker.go	Implements entity name visibility methods using resolver
internal/checker/nodebuilderimpl.go	Implements tryReuseExistingTypeNodeHelper with validation/tracking logic and fixes optionality handling

[jakebailey]

I would think this conflicts with #1693 / #2459