full type inference incorrectly infers known method types of builtins

[scoder]

In the following code, the type of 'append' is inferred as C function because 'flags.append' has been replaced by PyList_Append.

#cython: infer_types=True

cdef get_field_flags():
     flags = []
     append = flags.append

Also see #643.

[scoder]

Fixed here:

 https://github.com/cython/cython/commit/3ac5fb86833de2831e72bd368fab6b6f1fb03ec2