perf: make perfmanifest and perfnodelookup work with revsets...
perf: make perfmanifest and perfnodelookup work with revsets
They were using repo[rev], which only works with a single symbol
(e.g. "." or "my-bookmark"), not general revsets. Switch them to
scmutil.revsingle() so they can also be used with e.g. ".^".
I don't actually care about these commands, but I want to remove uses
of repo[<string>].
Differential Revision:
https://phab.mercurial-scm.org/D3083
