repoview: move changelog.revs() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7240

repoview: move changelog.__iter__() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7239

repoview: move changelog.__contains__() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7238

repoview: move changelog.tiprev() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7237

repoview: wrap changelog class when filtering The class doesn't yet do anything. I'll move the filter-aware overrides from the changelog class over one by one to this class in coming patches. That will leave the changelog class simpler and will centralize more of the filtering logic to repoview. I could not measure any performance difference. Differential Revision: https://phab.mercurial-scm.org/D7236

repoview: extract a function for wrapping changelog I would like to clean up the changelog class by moving out knowledge of filtering. The filtering will instead be done in a class that wraps the changelog. This patch prepares for that. Differential Revision: https://phab.mercurial-scm.org/D7235

revlog: move tiprev() from changelog up to revlog This makes the changelog override simpler and it seems more consistent. Differential Revision: https://phab.mercurial-scm.org/D7250

tests: fix a few `(no-windows !)` conditionals that are really `(symlink !)` The CI for py3 is assuming that symlinks are possible (they are when running as Administrator or when Developer Mode is enabled), and these popped up. Differential Revision: https://phab.mercurial-scm.org/D7232

rust-matchers: add `Matcher` trait and implement `AlwaysMatcher` In our quest of a faster Mercurial, we have arrived at the point where we need to implement the matchers in Rust. This RFC mainly for the `Matcher` trait to see if the changes proposed feel fine to people with more experience on the matter. While the `AlwaysMatcher` implementation is here as a trivial example, it should be the first step towards matchers use in Rust as it is currently the only supported one. Notable changes: - `exact` is renamed to `exact_match` - enums for `visit*` methods with `Recursive` instead of `'all'`, etc. - a new `roots`, separate from `file_set` - no `bad`, `explicitdir` or `traversedir` functions as they can be passed to the high functions instead of the matchers Thanks to Martin for suggesting the last two (most important) changes and for reaching out to help a few weeks ago. Differential Revision: https://phab.mercurial-scm.org/D7178

merge with stable