optimise calls on variables that reference builtin methods (e.g. pre-assigned unbound methods)

--HG--
extra : rebase_source : 4aeefab40694c611bfdaa4ecf56a3f4f6cdf3d04
fix build

--HG--
extra : rebase_source : 02f74a004499a227fc7edf2ccf3a1a9728c8951f
safety fix for analysis in assigned builtin methods optimisation

--HG--
extra : rebase_source : 8a7842eea9d10b4e8054ed3782e0efdc2b2ce02c
fix handler method signature

--HG--
extra : rebase_source : a7ab075312caa8eec32ba2763647b3a238404518