Bogus "Duplicate namespace" warning when using partial types

[masonwheeler]

Module 1:

import System

partial class MyClass:
   def constructor():
      print 'Hello MyClass!'

Module 2:

import System

partial class MyClass(object):
   override def ToString():
      return 'Hello from MyClass!'

Expected: this should compile without trouble.

Observed: compiler warning

Duplicate namespace: 'System'. (BCW0008)