language/go/fileinfo.go
func isIgnoredTag(tag string) bool {
	if tag == "cgo" || tag == "race" || tag == "msan" {
		return true
	}
	if len(tag) < 5 || !strings.HasPrefix(tag, "go") {
		return false
	}
	if tag[2] < '0' || tag[2] > '9' || tag[3] != '.' {
		return false
	}
	for _, c := range tag[4:] {
		if c < '0' || c > '9' {
			return false
		}
	}
	return true
}
func isIgnoredTag(tag string) bool {
	if tag == "cgo" || tag == "race" || tag == "msan" {
		return true
	}
	if len(tag) < 5 || !strings.HasPrefix(tag, "go") {
		return false
	}
	if tag[2] < '0' || tag[2] > '9' || tag[3] != '.' {
		return false
	}
	for _, c := range tag[4:] {
		if c < '0' || c > '9' {
			return false
		}
	}
	return true
}
// isIgnoredTag returns whether the tag is "cgo" or is a release tag.
// Release tags match the pattern "go[0-9]\.[0-9]+".
// Gazelle won't consider whether an ignored tag is satisfied when evaluating
// build constraints for a file.