runtime: enable vDSO support for s390x architecture
This change adds support for vDSO for s390x architecture. This avoids the use of system calls in nanotime and walltime and accelerates them by factor 4-5.
Benchmarks:
100,000,000 x time.Now():
syscall fallback 13923ms 139.23 ns/op
vDSO enabled 2640ms 26.40 ns/op
Change-Id: Ic679fe31048379e59ccf83b400140f13c9d49696
GitHub-Last-Rev:
8f6e918a45cf8c5aadc5c203949a8ce4e372086f
GitHub-Pull-Request: golang/go#49717
Reviewed-on: https://go-review.googlesource.com/c/go/+/365995
Run-TryBot: Paul Murphy <murp@ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Paul Murphy <murp@ibm.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Jonathan Albrecht <jonathan.albrecht@ibm.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>