This was a simple oversight: the algorithm to handle recursive types
needed to be applied to the ignore-item case as well.

Fixes #10415.

Change-Id: I39ef31cad680ab8334e141f60d2f8707896785d1
Reviewed-on: https://go-review.googlesource.com/8942Reviewed-by: Dmitry Vyukov <dvyukov@google.com>