[turbofan] Materialize all from non-writable roots from root array.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 1bc9a85b04b32759ea05a08a40b393035bb2556c..e30e40c121a607134596e0d7207037cd98900d4b 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -1211,10 +1211,6 @@ class Heap {
     kSmiRootsStart = kStringTableRootIndex + 1
   };
 
-  // Get the root list index for {object} if such a root list index exists.
-  bool GetRootListIndex(Handle<HeapObject> object,
-                        Heap::RootListIndex* index_return);
-
   Object* root(RootListIndex index) { return roots_[index]; }
 
   STATIC_ASSERT(kUndefinedValueRootIndex ==