Minor cleanups & trivial refactoring related to Ast.

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index e2ea93354688c3fd82a379cf91321995f50918f4..5f696b584eb50951a1741093f609e77eee4274c8 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -1352,20 +1352,6 @@ class Literal V8_FINAL : public Expression {
     return !value_->BooleanValue();
   }
 
-  // Identity testers.
-  bool IsNull() const {
-    ASSERT(!value_.is_null());
-    return value_->IsNull();
-  }
-  bool IsTrue() const {
-    ASSERT(!value_.is_null());
-    return value_->IsTrue();
-  }
-  bool IsFalse() const {
-    ASSERT(!value_.is_null());
-    return value_->IsFalse();
-  }
-
   Handle<Object> value() const { return value_; }
 
   // Support for using Literal as a HashMap key. NOTE: Currently, this works