compiler: Do not dereference a named pointer type when looking up a method.
compiler: Do not dereference a named pointer type when looking up a method.

Fixes #9018.

LGTM=iant
R=iant
CC=gofrontend-dev, gri
https://golang.org/cl/169010043

anlhord/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,golang/gofrontend,anlhord/gofrontend,golang/gofrontend,anlhord/gofrontend,anlhord/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend,golang/gofrontend,golang/gofrontend,qskycolor/gofrontend