compare-disco: support for `file` nodes specification
This leverage the `nodefromfile` feature in core. This make it possible for
callers to no longer pay the subset computation cost (and to make sure the
subset is the right one, even when the base repository is different)
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
end_of_line = lf
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true
end_of_line = lf
[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false
end_of_line = lf