match: drop support for empty pattern list in patternmatcher
Since the caller now deals with empty pattern lists, we can drop that
support in the patternmatcher. It now gets the more logical behavior
of matching nothing when no patterns are given (although there is no
in-core caller that will pass no patterns).
graft c-ext
graft zstd
include make_cffi.py
include setup_zstd.py
include zstd.c