const runtime.t4

4 uses

	runtime (current package)
		utf8.go#L25: 	t4 = 0xF0 // 1111 0000
		utf8.go#L79: 	case t3 <= s[0] && s[0] < t4:
		utf8.go#L88: 	case t4 <= s[0] && s[0] < t5:
		utf8.go#L126: 		p[0] = t4 | byte(r>>18)