Revert "go/types, types2: don't register interface methods in Info.Types map"
This reverts commit
4ac729283c807cdbe0f6c7041f21606019b722cf.
Reason for revert: changes semantics of types.Info.TypeOf; introduces new inconsistency around FieldList types.
For #74303
Change-Id: Ib99558c95f1b615fa9a02b028500ed230c8bb185
Reviewed-on: https://go-review.googlesource.com/c/go/+/683297
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Robert Findley <rfindley@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>