Support for non-decimal literals (oct, hex, bin) in autodoc signatures

[jaraco]

Is your feature request related to a problem? Please describe.

In jaraco/path#197, the user reports the unexpected default mode of a path argument renders as 511 instead of 0o777 as it appears in the source code, potentially confusing users and guiding them away from the best practice (to use octal literals for the mode).

Describe the solution you'd like

Ideally, the autodoc feature could parse the syntax tree and determine which literals are defined using non-decimal types and reflect that syntax in the documentation.

Short of that, it would be nice if there was a feature that allowed autodoc to selectively override the signature for affected functions/methods, such as a way to say "mode=511" should be rendered as "mode=0o777" at different scopes.

Describe alternatives you've considered

One option would be to render the docs once, then make the amendments, then periodically refresh the auto-generated docs to the code to keep it approximately in sync, merging with the amendments. Such an approach is probably more toil than it's worth.

I've also looked at the docs for automethod and autofunction, but I couldn't find any options that seem appropriate for overriding the rendering of the signature.

[tk0miya]

Thank you for posting. Same as #759.