log: expose std via new Default function
To allow passing around the package level *Logger, it is now exposed to
callers of the Default function. We considered exposing std, however at
this time there is no need to allow callers to replace std only pass and
call methods directly.
Fixes #39057
Change-Id: I710b16a3aa5e4e878870561dbf59560f98d8d09a
Reviewed-on: https://go-review.googlesource.com/c/go/+/264460
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Alberto Donizetti <alb.donizetti@gmail.com>