rust-chg: move get_umask() call out of run() function
run() will be an async function, but get_umask() isn't thread safe.
Differential Revision: https://phab.mercurial-scm.org/D8402
rust-chg: leverage impl trait at argument position
Differential Revision: https://phab.mercurial-scm.org/D8401
setup: link osutil.so to libsocket on Solaris/illumos (
issue6299)
revset: import `unstable()` from the evolve extension
Differential Revision: https://phab.mercurial-scm.org/D8404