[dev.typeparams] runtime/internal/sys: replace BigEndian with goarch.BigEndian [generated]

[git-generate]
cd src/runtime/internal/atomic
gofmt -w -r "sys.BigEndian -> goarch.BigEndian" .
goimports -w *.go
cd ../..
gofmt -w -r "sys.BigEndian -> goarch.BigEndian" .
goimports -w *.go

Change-Id: Iad35d2b367d8defb081a77ca837e7a7c805c2b7b
Reviewed-on: https://go-review.googlesource.com/c/go/+/329190


Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>