var go/build.knownOS

4 uses

	go/build (current package)
		build.go#L1959: 	if n >= 2 && knownOS[l[n-2]] && knownArch[l[n-1]] {
		build.go#L1962: 	if n >= 1 && (knownOS[l[n-1]] || knownArch[l[n-1]]) {
		build.go#L1968: var knownOS = make(map[string]bool)
		build.go#L1973: 		knownOS[v] = true