todo: support memoryview object newaxis indexing

minor fused cleanups

    This breaks comparing typedef types and results
    in funky things such as getting temporaries of
    different types.

This reverts commit e3838e42.

fused runtime dispatch for buffers

Infer variable as pyobject when del-ed, fix #768

Refactor none checking, allow nogil exceptions, nogil memoryview slice None comparison

Use assignments collected by CF for type inference