Expose a lower bound of malloc'd memory via heap statistics

test/unittests/compiler/loop-peeling-unittest.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/graph-visualizer.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/loop-peeling.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 46 matching lines @@
  protected:
   MachineOperatorBuilder machine_;
 
   MachineOperatorBuilder* machine() { return &machine_; }
 
   LoopTree* GetLoopTree() {
     if (FLAG_trace_turbo_graph) {
       OFStream os(stdout);
       os << AsRPO(*graph());
     }
-    Zone zone;
+    Zone zone(isolate()->allocator());
     return LoopFinder::BuildLoopTree(graph(), &zone);
   }
 
 
   PeeledIteration* PeelOne() {
     LoopTree* loop_tree = GetLoopTree();
     LoopTree::Loop* loop = loop_tree->outer_loops()[0];
     EXPECT_TRUE(LoopPeeler::CanPeel(loop_tree, loop));
     return Peel(loop_tree, loop);
   }
@@ skipping 413 matching lines @@
     LoopTree* loop_tree = GetLoopTree();
     LoopTree::Loop* loop = loop_tree->outer_loops()[0];
     EXPECT_FALSE(LoopPeeler::CanPeel(loop_tree, loop));
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8