runtime: add lock partial order edge between wakeableSleep and hchan

runtime: add lock partial order edge between wakeableSleep and hchan

This is totally valid and always was, but the staticlockranking builder
started failing when the new execution tracer was enabled by default.

Change-Id: I011e7d86bd968b1251bcc4d74395633036753b00
Reviewed-on: https://go-review.googlesource.com/c/go/+/544319
Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>