rust-status: add bare `hg status` support in hg-core
A lot of performance remains to be gained, most notably by doing more things
in parallel, but also by caching, not falling back to Python but switching
to another regex engine, etc..
I have measured on multiple repositories that this change, when in combination
with the next two patches, improve bare `hg status` performance, and has no
observable impact when falling back (because it does so early).
On the Netbeans repository:
C: 840ms
Rust+C: 556ms
Mozilla Central with the one pattern that causes a fallback removed:
C: 2.315s
Rust+C: 1.700 s
Differential Revision: https://phab.mercurial-scm.org/D7929
$ hg init a
$ cd a
$ hg init b
$ echo x > b/x
Should print nothing:
$ hg add b
$ hg st
$ echo y > b/y
$ hg st
Should fail:
$ hg st b/x
abort: path 'b/x' is inside nested repo 'b'
[255]
$ hg add b/x
abort: path 'b/x' is inside nested repo 'b'
[255]
Should fail:
$ hg add b b/x
abort: path 'b/x' is inside nested repo 'b'
[255]
$ hg st
Should arguably print nothing:
$ hg st b
$ echo a > a
$ hg ci -Ama a
Should fail:
$ hg mv a b
abort: path 'b/a' is inside nested repo 'b'
[255]
$ hg st
$ cd ..