hash/maphash: parallel run test
This is a reapplication of CL 564576.
This reduces the go test hash/maphash time
by more than half.
After investigation it was confirmed that
the original CL would cause OOM when 32-bit machine.
This CL add testenv.ParallelOn64Bit for tests
that can be parallel on 64-bit machines,
it is not parallel on 32-bit machines,
because CL 564995 require the same API.
Change-Id: I1b7feaa07716cb3f55db4671653348fabf2396b0
GitHub-Last-Rev:
28277255587f6a1b92b9bf1848e1f53adaca64dc
GitHub-Pull-Request: golang/go#66359
Cq-Include-Trybots: luci.golang.try:gotip-linux-386-longtest
Reviewed-on: https://go-review.googlesource.com/c/go/+/572195
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>