Remove AssignmentDeclarationMembers and GlobalExports from Symbol

[ahejlsberg]

This PR removes the rarely used AssignmentDeclarationMembers and GlobalExports fields from Symbol, shrinking it to the next size class down. Assignment declarations are now tracked in a symbol with an internal name and global exports (a.k.a. UMD namespace exports) are tracked in a map on the SourceFile object (only symbols associated with external modules would ever use the GlobalExports field, so a huge waste to have it in every symbol).

[Copilot]

Pull request overview

This PR refactors internal symbol bookkeeping to reduce ast.Symbol size by removing AssignmentDeclarationMembers and GlobalExports, relocating that state to more targeted structures in the compiler/LS pipeline.

Changes:

• Move UMD namespace (“global exports”) tracking from Symbol.GlobalExports to SourceFile.GlobalExports.
• Replace Symbol.AssignmentDeclarationMembers with an internal export entry keyed by ast.InternalSymbolNameAssignmentDeclaration.
• Update checker and language service logic to use the new storage locations.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
internal/ls/importTracker.go	Updates UMD-global availability detection to consult SourceFile.GlobalExports via the module symbol’s ValueDeclaration.
internal/ls/findallreferences.go	Adjusts symbol-scope logic for external modules/UMD globals, but introduces a scoping regression for ambient external modules.
internal/checker/checker.go	Switches UMD export merging to SourceFile.GlobalExports and updates late-bound assignment handling to read from the new internal export symbol.
internal/binder/binder.go	Writes namespace exports into SourceFile.GlobalExports and stores late-bound assignment declarations under an internal export symbol.
internal/ast/symbol.go	Removes the two fields from Symbol and introduces InternalSymbolNameAssignmentDeclaration.
internal/ast/ast.go	Adds GlobalExports SymbolTable to SourceFile.

[Copilot]

The new exposedByParent gate no longer checks whether symbol.Parent is an external module symbol; it only checks for a SourceFile value declaration. For ambient external modules (declare module "a" { ... }), the module symbol's ValueDeclaration is a ModuleDeclaration, so this condition will treat exports as globally visible and return nil scope, widening the reference search incorrectly. Consider restoring the external-module check (e.g. symbol.Parent.IsExternalModule() / checker.IsExternalModuleSymbol(symbol.Parent)) and then consulting GlobalExports only when the module symbol's ValueDeclaration is a SourceFile.

Suggested change

	if exposedByParent && !(symbol.Parent.ValueDeclaration != nil && ast.IsSourceFile(symbol.Parent.ValueDeclaration) && symbol.Parent.ValueDeclaration.AsSourceFile().GlobalExports == nil) {
	return nil
	if exposedByParent {
	// If the parent is not an external module symbol, the symbol is globally visible.
	if !checker.IsExternalModuleSymbol(symbol.Parent) {
	return nil
	}
	// For external modules, only treat exports as globally visible when the module
	// is a SourceFile with `export as namespace` (non-nil GlobalExports).
	if symbol.Parent.ValueDeclaration != nil && ast.IsSourceFile(symbol.Parent.ValueDeclaration) {
	sourceFile := symbol.Parent.ValueDeclaration.AsSourceFile()
	if sourceFile.GlobalExports != nil {
	return nil
	}
	}

[ahejlsberg]

If the symbol's ValueDeclaration is a source file, we know we have an external module, so no need for other checks.

[jakebailey]

Even for declare module blocks?

[ahejlsberg]

declare module blocks don't permit export as namespace declarations, so nothing to check there.

[ahejlsberg]

Anyways, with the latest commit the code is now equivalent to what was there before.

[jakebailey]

This func is the same as the one in findallreferences.go; worth pulling into a helper?