Add test case for symbol property key import in declaration emit

Co-authored-by: DanielRosenwasser <972891+DanielRosenwasser@users.noreply.github.com>

Author: Copilot

tests/cases/compiler/declarationEmitSymbolPropertyKey.ts

@@ -0,0 +1,22 @@
+// @target: es2015
+// @declaration: true
+// @module: commonjs
+
+// @filename: node_modules/test-pkg/index.d.ts
+declare const lostSymbol: unique symbol;
+type lostSymbol = typeof lostSymbol;
+
+type SomeGeneric<T> = {
+    [lostSymbol]: T;
+};
+
+declare function fn(): SomeGeneric<unknown>;
+
+export {
+    lostSymbol,
+    fn
+};
+
+// @filename: index.ts
+import { fn } from 'test-pkg';
+export const value = fn();