[release-branch.go1.11] cmd/cgo: don't cache bad pointer typedefs
The set of bad pointer typedefs changes as we see more typedefs, so
avoid looking in the cache when we find one.
Updates #29175
Fixes #29272
Change-Id: Idd82289bdd8628d11a983fa5ec96517e3a5bcbf1
Reviewed-on: https://go-review.googlesource.com/c/153597
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
(cherry picked from commit
01e072db5d26c224dfbe7763a5b94ab23c163983)
Reviewed-on: https://go-review.googlesource.com/c/154299
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>