perf: use the `perf--` prefix for perf command
This is the one command namespace where they should not be any ambiguity about
command that should be in it. The perf extensions is only adding performance
related command.
so this is a good ground to start putting dash folding to the tests.
Differential Revision: https://phab.mercurial-scm.org/D9516
missing lfs pointer keys: oid, size
ok
unexpected lfs pointer value: version='https://unknown.github.com/spec/v1'
cannot parse git-lfs text: 'version https://git-lfs.github.com/spec/v1\n\noid sha256:4d7a214614ab2935c943f9e0ff69d22eadbb8f32b1258daaa5e2ca24d17e2393\nsize 12345\nx-foo extra-information\n'
unexpected lfs pointer value: oid='ahs256:4d7a214614ab2935c943f9e0ff69d22eadbb8f32b1258daaa5e2ca24d17e2393'
unexpected lfs pointer value: oid='4d7a214614ab2935c943f9e0ff69d22eadbb8f32b1258daaa5e2ca24d17e2393'
unexpected lfs pointer value: size='0x12345'
ok
cannot parse git-lfs text: 'version https://git-lfs.github.com/spec/v1\noid sha256:4d7a214614ab2935c943f9e0ff69d22eadbb8f32b1258daaa5e2ca24d17e2393\nsize 12345\nx-foo extra\ninformation\n'
unexpected lfs pointer key: x_foo
missing lfs pointer keys: oid
missing lfs pointer keys: oid, size