Implemented support for generalized void in analyzer.

tests/language/syntax_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class SyntaxTest {
   // "this" cannot be used as a field name.
   SyntaxTest this; //# 01: compile-time error
 
   // Syntax error.
   foo {} //# 02: compile-time error
@@ skipping 207 matching lines @@
     f(void) {}; //# 54: compile-time error
 
     optionalArg([x]) {}
     optionalArg(
       void (var i) {} //# 55: compile-time error
         );
 
     function __PROTO__$(...args) { return 12; } //# 56: compile-time error
     G<> t; //# 57: compile-time error
     G<null> t; //# 58: compile-time error
-    A<void> a = null; //# 59: compile-time error
-    void v; //# 60: compile-time error
-    void v = null; //# 61: compile-time error
-    print(null is void); //# 62: compile-time error
+    A<void> a = null;
+    void v;
+    void v = null;
+    print(null is void); //# 59: compile-time error
     new A();
     new B();
 
     new Bad();
 
-    1 + 2 = 1; //# 63: compile-time error
-    new SyntaxTest() = 1; //# 64: compile-time error
-    futureOf(null) = 1; //# 65: compile-time error
+    1 + 2 = 1; //# 60: compile-time error
+    new SyntaxTest() = 1; //# 61: compile-time error
+    futureOf(null) = 1; //# 62: compile-time error
 
     new C();
   } catch (ex) {
     // Swallowing exceptions. Any error should be a compile-time error
     // which kills the current isolate.
   }
 }
 
 class Bad {
   factory Bad<Bad(String type) { return null; } //# 63: compile-time error
 }
 
 class C {
-  void f; // //# 66: compile-time error
-  static void g; // //# 67: compile-time error
+  void f;
+  static void g;
 }