This test was added recently as a regress test for the spec relaxation
in #9060, but doesn't work correctly yet. Disable for now to fix noopt
builders.

Updates #22444.

Change-Id: I45c521ae0da7ffb0c6859d6f7220c59828ac6149
Reviewed-on: https://go-review.googlesource.com/81775
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>