Heap::kNew-space allocations discovered by experimental code called transitively from parser

runtime/vm/isolate_reload.cc

Index: runtime/vm/isolate_reload.cc
diff --git a/runtime/vm/isolate_reload.cc b/runtime/vm/isolate_reload.cc
index 414d09381d200b545b70c0a38051459728be7825..52734d07bffa45fb1d391d5e9cecadc2b0c9a817 100644
--- a/runtime/vm/isolate_reload.cc
+++ b/runtime/vm/isolate_reload.cc
@@ -572,12 +572,14 @@ void IsolateReloadContext::Reload(bool force_reload,
   // Preallocate storage for maps.
   old_classes_set_storage_ =
       HashTables::New<UnorderedHashSet<ClassMapTraits> >(4);
-  class_map_storage_ = HashTables::New<UnorderedHashMap<ClassMapTraits> >(4);
+  class_map_storage_ =
+      HashTables::New<UnorderedHashMap<ClassMapTraits> >(4, Heap::kOld);
   old_libraries_set_storage_ =
       HashTables::New<UnorderedHashSet<LibraryMapTraits> >(4);
   library_map_storage_ =
       HashTables::New<UnorderedHashMap<LibraryMapTraits> >(4);
-  become_map_storage_ = HashTables::New<UnorderedHashMap<BecomeMapTraits> >(4);
+  become_map_storage_ =
+      HashTables::New<UnorderedHashMap<BecomeMapTraits> >(4, Heap::kOld);
   // Keep a separate array for enum mappings to avoid having to invoke
   // hashCode on the instances.
   become_enum_mappings_ = GrowableObjectArray::New(Heap::kOld);
@@ -1760,7 +1762,7 @@ RawLibrary* IsolateReloadContext::OldLibraryOrNullBaseMoved(
   const intptr_t old_prefix_length = old_url_prefix.Length();
   const String& new_url = String::Handle(replacement_or_new.url());
   const String& suffix =
-      String::Handle(String::SubString(new_url, prefix_length));
+      String::Handle(String::SubString(new_url, prefix_length, Heap::kOld));
   if (!new_url.StartsWith(url_prefix)) {
     return Library::null();
   }
@@ -1776,7 +1778,7 @@ RawLibrary* IsolateReloadContext::OldLibraryOrNullBaseMoved(
     if (!old_url.StartsWith(old_url_prefix)) {
       continue;
     }
-    old_suffix ^= String::SubString(old_url, old_prefix_length);
+    old_suffix ^= String::SubString(old_url, old_prefix_length, Heap::kOld);
     if (old_suffix.IsNull()) {
       continue;
     }