go/types, types2: added clarifying comments, removed TODO in lookup.go
Also, renamed lookupFieldOrMethod to lookupFieldOrMethodImpl to make
a clearer distinction between this function and the exported version
LookupFieldOrMethod.
Except for the rename, all changes are to comments only.
Change-Id: If7d1465c9cf659ea86bbbbcba8b95f16d2170fcc
Reviewed-on: https://go-review.googlesource.com/c/go/+/473075 Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com> Reviewed-by: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>