Remove unused function.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 87a7efd4940210d30be68cb8828625e360362f80..3495eab82245fead91a41bd85b914c812326bc32 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -1116,11 +1116,6 @@ void HeapObject::IterateBody(InstanceType type, int object_size,
 }
 
 
-void HeapObject::IterateStructBody(int object_size, ObjectVisitor* v) {
-  IteratePointers(v, HeapObject::kHeaderSize, object_size);
-}
-
-
 Object* HeapNumber::HeapNumberToBoolean() {
   // NaN, +0, and -0 should return the false object
 #if __BYTE_ORDER == __LITTLE_ENDIAN