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

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

Index: test/unittests/compiler/loop-peeling-unittest.cc
diff --git a/test/unittests/compiler/loop-peeling-unittest.cc b/test/unittests/compiler/loop-peeling-unittest.cc
index 9dcec85ebf77d96b6e468f65fe42110dd9f87294..9db490560dded5fcbb9c1af2f0a5907871d13de6 100644
--- a/test/unittests/compiler/loop-peeling-unittest.cc
+++ b/test/unittests/compiler/loop-peeling-unittest.cc
@@ -64,7 +64,7 @@ class LoopPeelingTest : public GraphTest {
       OFStream os(stdout);
       os << AsRPO(*graph());
     }
-    Zone zone;
+    Zone zone(isolate()->allocator());
     return LoopFinder::BuildLoopTree(graph(), &zone);
   }