go/types, cmd/compile: add simd/.../sgutil to the TestStdlib ignores

Fixes #79677.

Change-Id: Ic7f16bb80ea60656e3e1f45685eabc8c1f6f3bba
Reviewed-on: https://go-review.googlesource.com/c/go/+/783602
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>