Add a first class GrowableObjectArray type in the VM and use it internally in the VM at all spots w…

vm/snapshot.cc

Index: vm/snapshot.cc
===================================================================
--- vm/snapshot.cc	(revision 5060)
+++ vm/snapshot.cc	(working copy)
@@ -307,6 +307,12 @@
 }
 
 
+RawGrowableObjectArray* SnapshotReader::NewGrowableObjectArray() {
+  ALLOC_NEW_OBJECT(GrowableObjectArray,
+                   object_store()->growable_object_array_class());
+}
+
+
 RawClass* SnapshotReader::LookupInternalClass(intptr_t class_header) {
   SerializedHeaderType header_type = SerializedHeaderTag::decode(class_header);