THRIFT-2112 Error in Go generator when using typedefs in map keys

Patch: Emir Habul
diff --git a/lib/go/test/IncludesTest.thrift b/lib/go/test/IncludesTest.thrift
index 6f80e6b..3f60321 100644
--- a/lib/go/test/IncludesTest.thrift
+++ b/lib/go/test/IncludesTest.thrift
@@ -55,3 +55,13 @@
   void extendedMethod3(),
 }
 
+typedef map<ThriftTest.UserId, map<NamespacedTest.UserId, list<TestStruct2> > > ComplexMapType
+
+struct ComplexMapStruct {
+  1: ComplexMapType complex,
+}
+
+service ComplexMapService {
+  ComplexMapStruct transformMap(1: ComplexMapStruct input),
+}
+