fuzzers: init Python in LLVMFuzzerInitialize and intentionally leak it This sidesteps leaks (or "leaks", I'm not sure) in CPython, and lets our fuzzer work. Differential Revision: https://phab.mercurial-scm.org/D4906

revlog: if the module is initialized more than once, don't leak nullentry Caught (annoyingly) by the manifest fuzzer. Differential Revision: https://phab.mercurial-scm.org/D4905

narrow: move remaining narrow-limited dirstate walks to core In most places we now filter at a higher level (the context object), but there are few places that relied on the dirstate walk to be filtered by the narrowspec. The important cases are those used by `hg add` and `hg addremove`. This patch updates them to pass in a matcher instead of relying on the dirstate to do the filtering. The dirstate filtering is also dropped in narrowdirstate.py. Not always filtering in the dirstate should be useful for a future `hg status --include-outside-narrow` option. These places now end up doing an unrestricted dirstate walk after this patch: * debugfileset * perfwalk * sparse (but restricted to sparse config) * largefiles I'll let anyone who cares about these cases adapt them to work with narrow if necessary. Differential Revision: https://phab.mercurial-scm.org/D4901

narrow: allow repo.narrowmatch(match) to include exact matches from "match" Differential Revision: https://phab.mercurial-scm.org/D4900