internal/fuzz: disconnect stdout and stderr from the worker
This was useful for debugging while we were developing
the feature, but is now causing extraneous prints that
make the command output difficult to read.
This change also prevents the go command from printing
an extraneous "FAIL" when fuzzing is enabled.
Fixes #48633
Fixes #46631
Change-Id: I636e65f305a20f6dcd843e62090ae228741a3725
Reviewed-on: https://go-review.googlesource.com/c/go/+/352892
Trust: Katie Hockman <katie@golang.org>
Run-TryBot: Katie Hockman <katie@golang.org> Reviewed-by: Jay Conrod <jayconrod@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>