[dev.fuzz] cmd/go: 'go clean -fuzzcache' should not delete compiled files
This change adds -fuzzcache to the list of flags that prevents 'go clean'
from cleaning packages by default.
Fixes #47478
Change-Id: I07c9c24ff6359e45e9661b307a671274ab2d7212
GitHub-Last-Rev:
4929618c1fedafc3712a9ffdd1691a92042334eb
GitHub-Pull-Request: golang/go#47483
Reviewed-on: https://go-review.googlesource.com/c/go/+/338752
Reviewed-by: Jay Conrod <jayconrod@google.com>
Trust: Jay Conrod <jayconrod@google.com>
Trust: Roland Shoemaker <roland@golang.org>
Trust: Bryan C. Mills <bcmills@google.com>