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

test/cctest/test-field-type-tracking.cc

Index: test/cctest/test-field-type-tracking.cc
diff --git a/test/cctest/test-field-type-tracking.cc b/test/cctest/test-field-type-tracking.cc
index 3b93b815fb9cd02b8c040a7da97ed97bb60964df..dcf2c56006a41404b96bec659eaf37e8ecb474ff 100644
--- a/test/cctest/test-field-type-tracking.cc
+++ b/test/cctest/test-field-type-tracking.cc
@@ -574,7 +574,7 @@ static void TestGeneralizeRepresentation(
   CHECK(map->is_stable());
   CHECK(expectations.Check(*map));
 
-  Zone zone;
+  ZoneForTesting zone;
 
   if (is_detached_map) {
     detach_point_map = Map::ReconfigureProperty(
@@ -966,7 +966,7 @@ static void TestReconfigureDataFieldAttribute_GeneralizeRepresentation(
   CHECK(map2->is_stable());
   CHECK(expectations2.Check(*map2));
 
-  Zone zone;
+  ZoneForTesting zone;
   Handle<Map> field_owner(map->FindFieldOwner(kSplitProp), isolate);
   CompilationInfo info("testing", isolate, &zone);
   CHECK(!info.dependencies()->HasAborted());
@@ -1051,7 +1051,7 @@ static void TestReconfigureDataFieldAttribute_GeneralizeRepresentationTrivial(
   CHECK(map2->is_stable());
   CHECK(expectations2.Check(*map2));
 
-  Zone zone;
+  ZoneForTesting zone;
   Handle<Map> field_owner(map->FindFieldOwner(kSplitProp), isolate);
   CompilationInfo info("testing", isolate, &zone);
   CHECK(!info.dependencies()->HasAborted());