crypto: check all cpu.X86 flags for features used in assembly
These are most likely redundant, but cmd/compile/internal/amd64's
TestGoAMD64v1 turns them off when clobbering those instructions, so we
need to know to skip the assembly in those cases.
Thankfully we have Avo now that adds a helpful comment with the list of
features used by each generated function!
Also improve the error output of TestGoAMD64v1. It had broken before in
#49402 and had required the exact same patch.
Change-Id: I7fab8f36042cdff630f806723aa1d8124c294f60
Reviewed-on: https://go-review.googlesource.com/c/go/+/626876
Auto-Submit: Filippo Valsorda <filippo@golang.org> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Russ Cox <rsc@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>