Fix broken build by removing more const qualifiers.

Review URL: http://codereview.chromium.org/6532085

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6867 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.cc

@@ -928,7 +928,7 @@ void HPhi::AddInput(HValue* value) {
 }
 
 
-HValue* HPhi::GetRedundantReplacement() const {
+HValue* HPhi::GetRedundantReplacement() {
   HValue* candidate = NULL;
   int count = OperandCount();
   int position = 0;