runtime: pass nanotime and gomaxprocs into startCycle and endCycle explicitly
This is to facilitate testing of the pacer, since otherwise this is
accessing global state, which is impossible to stub out properly.
For #44167.
Change-Id: I52c3b51fc0ffff38e3bbe534bd66e5761c0003a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/353353
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com>