func isArmArch(arch string) bool {
	switch arch {
	case "arm", "arm64":
		return true
	}
	return false
}
isArmArch returns true if the architecture is ARM.

The arch value should be normalized before being passed to this function.
package platforms
import (
	"runtime"
	"strings"
)
func isLinuxOS(os string) bool {
	return os == "linux"
}
func isKnownOS(os string) bool {
	switch os {
	case "aix", "android", "darwin", "dragonfly", "freebsd", "hurd", "illumos", "js", "linux", "nacl", "netbsd", "openbsd", "plan9", "solaris", "windows", "zos":
		return true
	}
	return false
}