Perhaps also explain that Select(*T, false, ...) is not equivalent to Select(T, true, ...) since the former selects only methods whose receiver is *T but the latter may select a method whose receiver is T or *T.

Unfortunate. API is frozen.

While you were travelling, Russ explicitly exempted API cleanups to go/types from the freeze since they would not break any existing packages, and this one is less disruptive than both the Scope-to-Block renaming I proposed and the MethodSet move you proposed.

Please re-open this ticket.

Even though we can't rename the existing LookupFieldOrMethod, there's still a gap in the API.

Consider (*ssa.Program).MethodValue(sel *types.Selection) *ssa.Function. It requires a *types.Selection as its argument. If you have the receiver type T and the selector name (pkg, name), you can obtain a Selection by calling types.NewMethodSet(T).Lookup(pkg, name), but this is asymptotically more expensive than calling types.LookupFieldOrMethod(T, false, pkg, name).

Ideally the client would be able to call LookupFieldOrMethod and then construct a Selection (field or method) from the result, but there is no way for clients to construct a Selection.

Could we expose a NewSelection constructor?

Closed in favor of new issue #12881.