fix static member expression calls, make classes more spec-compliant

test/fixtures/syntax/modules/exports-default/expected.js

@@ -8,15 +8,13 @@ exports.default = foo;
 exports.default = function () {}
 
 exports.default = function () {
-  function Anonymous() {
-  }
-  return Anonymous;
+  var _class = function() {};
+  return _class;
 }();
 
 exports.default = function foo () {}
 
 exports.default = function () {
-  function foo() {
-  }
+  var foo = function foo() {};
   return foo;
 }();

test/fixtures/syntax/modules/exports-variable/expected.js

@@ -25,8 +25,7 @@ var foo8;
   function foo7 () {}
 
   foo8 = function () {
-    function foo8() {
-    }
+    var foo8 = function foo8() {};
     return foo8;
   }();
   exports.foo8 = foo8;