Added test for find all refs of function expressions.

tests/cases/fourslash/findAllRefsForFunctionExpression01.ts

@@ -0,0 +1,21 @@
+/// <reference path='fourslash.ts'/>
+
+// @Filename: file1.ts
+////var foo = function [|foo|](a = [|foo|](), b = () => [|foo|]) {
+////    [|foo|]([|foo|], [|foo|]);
+////}
+
+// @Filename: file2.ts
+/////// <reference path="file1.ts" />
+////foo();
+
+
+let ranges = test.ranges()
+for (let range of ranges) {
+    goTo.position(range.start);
+
+    verify.referencesCountIs(ranges.length);
+    for (let expectedReference of ranges) {
+        verify.referencesAtPositionContains(expectedReference);
+    }
+}