x/tools/go/types/objectpath: remove sorting of Named type methods

[findleyr]

As we've seen in #58668 (comment), the sorting of Named type methods can dominate the cost of using the objectpath package. In the example there, both gopls and the staticcheck analysis driver are essentially unusable when Named type methods are sorted.

Proposal: We propose to remove this sorting, effectively reverting the fix for #44195. We should instead guarantee in our documentation that the order of methods is deterministic, both the compiler and go/types agree on this sorting, and this sorting is preserved by all importers/exporters.

(Aside: I'm going to remove the sorting (conditionally) in gopls now, because this has a large impact on gopls usability. However, whatever back-channels I use to do so should be short-lived, and we should agree on a path forward that works for everyone.)

CC @adonovan @dominikh @griesemer @mdempsky

[gopherbot]

Change https://go.dev/cl/517737 mentions this issue: go/types/objectpath: remove use of linkname for gopls back doors

[findleyr]

Elevating this to a proposal, per discussion with @rsc. We need to decide whether it's ok to revert this behavior. Otherwise, we need to propose a new API that disables sorting.

[dominikh]

The current behavior of objectpath is quite under-defined. It doesn't say anything about sorting, the stability of paths, what will cause them to change, etc.

[rsc]

This proposal has been added to the active column of the proposals project
and will now be reviewed at the weekly proposal review meetings.
— rsc for the proposal review group

[rsc]

Have all concerns about this proposal been addressed?

[rsc]

Based on the discussion above, this proposal seems like a likely accept.
— rsc for the proposal review group

[gopherbot]

Change https://go.dev/cl/534139 mentions this issue: go/types/objectpath: remove method sorting

[rsc]

No change in consensus, so accepted. 🎉
This issue now tracks the work of implementing the proposal.
— rsc for the proposal review group