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

src/runtime/runtime-internal.cc

Index: src/runtime/runtime-internal.cc
diff --git a/src/runtime/runtime-internal.cc b/src/runtime/runtime-internal.cc
index 944073d32121f564fe486f6fdfca8180c9e2b905..b1bec57956e0a06a24d9f7257d601a3950541793 100644
--- a/src/runtime/runtime-internal.cc
+++ b/src/runtime/runtime-internal.cc
@@ -386,7 +386,7 @@ bool ComputeLocation(Isolate* isolate, MessageLocation* target) {
 Handle<String> RenderCallSite(Isolate* isolate, Handle<Object> object) {
   MessageLocation location;
   if (ComputeLocation(isolate, &location)) {
-    Zone zone;
+    Zone zone(isolate->allocator());
     base::SmartPointer<ParseInfo> info(
         location.function()->shared()->is_function()
             ? new ParseInfo(&zone, location.function())