[release-branch.go1.1] test: do not run the test that relies on precise GC on 32-bits

««« CL 9573043 / c0f8999bd970
test: do not run the test that relies on precise GC on 32-bits
Currently most of the 32-bit builder are broken.
Fixes #5516.

R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/9573043
»»»

R=dvyukov, iant, minux.ma, bradfitz
CC=golang-dev
https://golang.org/cl/10032043