Oilpan: remove unused typed pointer cast operation over (Weak)Member.

Source/platform/heap/Handle.h

Index: Source/platform/heap/Handle.h
diff --git a/Source/platform/heap/Handle.h b/Source/platform/heap/Handle.h
index d1caccc48f349bec642a959863dbe8ee1ef4e86f..339d4f3a75831107d1add441d63e5c39f8418675 100644
--- a/Source/platform/heap/Handle.h
+++ b/Source/platform/heap/Handle.h
@@ -351,12 +351,6 @@ public:
         m_raw = nullptr;
     }
 
-    template<typename U>
-    U* as() const
-    {
-        return static_cast<U*>(m_raw);
-    }
-
     void trace(Visitor* visitor)
     {
         STATIC_ASSERT_IS_GARBAGE_COLLECTED(T, "non-garbage collected object should not be in Persistent");
@@ -569,12 +563,6 @@ public:
         return result;
     }
 
-    template<typename U>
-    U* as() const
-    {
-        return static_cast<U*>(m_raw);
-    }
-
     bool operator!() const { return !m_raw; }
 
     operator T*() const { return m_raw; }