Rename static methods to avoid shadowing virtual methods

and fix Clang C++11 compile error.

Review URL: https://chromiumcodereview.appspot.com/9420049

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10739 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

build/common.gypi

@@ -306,7 +306,7 @@
           }],
           ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd"', {
             'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
-                        '-Wnon-virtual-dtor' ],
+                        '-Wnon-virtual-dtor', '-Woverloaded-virtual' ],
           }],
         ],
       },  # Debug

src/objects.h

@@ -1011,7 +1011,7 @@ class Smi: public Object {
   void SmiVerify();
 #endif
 
-  static const int kMinValue = (-1 << (kSmiValueSize - 1));
+  static const int kMinValue = (-1U << (kSmiValueSize - 1));
   static const int kMaxValue = -(kMinValue + 1);
 
  private: