Precompilation: Including generative constructor entry points should mark a class as instantiated.

runtime/vm/precompiler.cc

Index: runtime/vm/precompiler.cc
diff --git a/runtime/vm/precompiler.cc b/runtime/vm/precompiler.cc
index 23b67b1dcc4a7c1661c849bfa38a8fa13022ee2a..039c2bf6a608ae678cd22a1e3154011f9fb83f0d 100644
--- a/runtime/vm/precompiler.cc
+++ b/runtime/vm/precompiler.cc
@@ -282,6 +282,13 @@ void Precompiler::AddEntryPoints(Dart_QualifiedFunctionName entry_points[]) {
     }
 
     AddFunction(func);
+    if (func.IsGenerativeConstructor()) {
+      // Allocation stubs are referenced from the call site of the constructor,
+      // not in the constructor itself. So compiling the constructor isn't
+      // enough for us to discover the class is instantiated if the class isn't
+      // otherwise instantiated from Dart code and only instantiated from C++.
+      AddClass(cls);

[srdjan, 2015/10/16 20:10:21]

Maybe AddInstantiatedClass?

[rmacnak, 2015/10/16 20:31:02]

That's better.

+    }
   }
 }