Revert "runtime: speed up receive on empty closed channel"

This reverts CL 181543 (git e1446d9c)

Reason for revert: Caused a regression in the race detector.

Updates #32529
Fixes #36714

Change-Id: Ifefe6784f86ea72f414a89f131c239e9c9fd74eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/216158


Run-TryBot: Alexander Rakoczy <alex@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>