Allow arbitrary names for weak references in heap snapshots.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index a00e6080145aaafab13bea181c366e1fb87c9743..064a4b013f45e22b2327c4a451fae928cbfff27e 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6944,11 +6944,11 @@ Handle<Value> HeapGraphEdge::GetName() const {
     case i::HeapGraphEdge::kInternal:
     case i::HeapGraphEdge::kProperty:
     case i::HeapGraphEdge::kShortcut:
+    case i::HeapGraphEdge::kWeak:
       return ToApiHandle<String>(
           isolate->factory()->InternalizeUtf8String(edge->name()));
     case i::HeapGraphEdge::kElement:
     case i::HeapGraphEdge::kHidden:
-    case i::HeapGraphEdge::kWeak:
       return ToApiHandle<Number>(
           isolate->factory()->NewNumberFromInt(edge->index()));
     default: UNREACHABLE();