<rdar://problem/12831670>

For iOS native lldb, don't initialize the ModuleList notifier
callback.  See the added comment for details on how this is a problem
in that environment.  We'll need to restructure how the ModuleDidLoad
notification is called vrs. when the DynamicLoader pluging has had
a chance to set the Sectino load addresses.

llvm-svn: 170082