internal/fuzz: log average execs/sec since last log
This change also fixes a bug with calculating the
total interesting count. When fuzzing with an empty
corpus, the fuzzing engine adds an starting corpus
value in that run in order to start fuzzing. That
meant that the interesting total count was off by one:
it would start at 1, even though the cache was empty.
Added some tests for this as well.
Fixes #48787
Change-Id: I47acf96f0a0797214ebb24a95366d8460bf303bc
Reviewed-on: https://go-review.googlesource.com/c/go/+/354150
Trust: Katie Hockman <katie@golang.org>
Run-TryBot: Katie Hockman <katie@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Jay Conrod <jayconrod@google.com> Reviewed-by: Roland Shoemaker <roland@golang.org>