Merge pull request #1217 from Microsoft/QuickInfoRequire

Fix for crash in QuickInfo on module path in import statement.

tests/cases/fourslash/quickInfoForRequire.ts

@@ -0,0 +1,11 @@
+/// <reference path='fourslash.ts'/>
+
+//@Filename: AA/BB.ts
+////export class a{}
+
+//@Filename: quickInfoForRequire_input.ts
+////import a = require("AA/B/*1*/B");
+
+goTo.marker('1');
+verify.quickInfoIs('module a');
+verify.referencesCountIs(0);