Drop dangling local symbol occurrences

[eseliger]

Concrete failure before this change

Given two indexed packages:

// package A
export function localResult() {
  interface LocalResult {
    value: string
  }
  return { value: '' } as LocalResult
}

// package B
localResult().value

Package B previously emitted a reference local 1 occurrence for value, but its document contained no SymbolInformation for local 1. SCIP local symbols are scoped to one document, so package A's local symbol could not satisfy that reference. This change drops that dangling cross-document occurrence while preserving the valid local definitions and references inside package A.

Longer-term

Ideally, package B's value reference should navigate to the LocalResult.value definition in package A. SCIP can represent that by assigning the private property a stable declaration-derived global identity—global in the SCIP uniqueness sense, not exported in the TypeScript visibility sense—likely owned by the exported function whose return type exposes it. Both the definition in package A and references in other documents would then use that identity.

That promotion requires deterministic handling for private declarations exposed through exported inferred or structural types. This PR intentionally implements the safe correctness fallback first: omitting an unrepresentable reference is preferable to emitting an invalid dangling local symbol.