Remove unused method HType::IsTagged().

BUG=
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/24087004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16610 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.h

@@ -374,10 +374,6 @@ class HType V8_FINAL {
     return Combine(other).Equals(other);
   }
 
-  bool IsTagged() const {
-    return ((type_ & kTagged) == kTagged);
-  }
-
   bool IsTaggedPrimitive() const {
     return ((type_ & kTaggedPrimitive) == kTaggedPrimitive);
   }