It's easier to understand what's happening after inlining these into
noder.typeDecl.

Change-Id: I7beed5a1e18047bf09f2d4ddf64b9646c324d8d6
Reviewed-on: https://go-review.googlesource.com/36111
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>