cmd/go: limit GOMAXPROCS in TestScript/test_fuzz_.*
This limits the throughput and resource consumption of the fuzz
workers in the tests, which also reduces the likelihood of running out
of address space in the fuzz coordinator during the test.
(Ideally the coordinator should not be limited by address space;
this just works around the failure mode in the tests for now.)
For #65434.
Change-Id: I3086c6278d6803a3dbf17a46ed01b68cedc92ad9
Cq-Include-Trybots: luci.golang.try:gotip-linux-386-longtest,gotip-windows-amd64-longtest
Reviewed-on: https://go-review.googlesource.com/c/go/+/560515 Reviewed-by: Roland Shoemaker <roland@golang.org>
Auto-Submit: Bryan Mills <bcmills@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>