const unicode/utf8.runeErrorByte0

3 uses

	unicode/utf8 (current package)
		utf8.go#L65: 	runeErrorByte0 = t3 | (RuneError >> 12)
		utf8.go#L380: 		p[0] = runeErrorByte0
		utf8.go#L408: 		return append(p, runeErrorByte0, runeErrorByte1, runeErrorByte2)