Add ImmutableHeap class consisting of parts

src/vm/object_memory.cc

 // Copyright (c) 2014, the Fletch project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE.md file.
 
 #include "src/vm/object_memory.h"
 
 #include <stdlib.h>
 #include <stdio.h>
 
 #include "src/shared/assert.h"
@@ skipping 104 matching lines @@
 }
 
 void Space::TryDealloc(uword location, int size) {
   if (top_ == location) top_ -= size;
 }
 
 void Space::AdjustAllocationBudget() {
   allocation_budget_ = Utils::Maximum(512 * KB, Used());
 }
 
+void Space::SetAllocationBudget(int new_budget) {
+  allocation_budget_ = new_budget;
+}
+
 void Space::PrependSpace(Space* space) {
   bool was_empty = is_empty();
 
   if (space->is_empty()) return;
 
   space->Flush();
 
   Chunk* first = space->first();
   Chunk* chunk = first;
   while (chunk != NULL) {
@@ skipping 252 matching lines @@
       table = GetPageTable(address);
       if (table == NULL) {
         SetPageTable(address, table = new PageTable(address & ~0x3fffff));
       }
     }
     table->Set((address >> 12) & 0x3ff, space);
   }
 }
 
 }  // namespace fletch