const regexp/syntax.opPseudo

5 uses

	regexp/syntax (current package)
		parse.go#L75: 	opLeftParen = opPseudo + iota
		parse.go#L238: 	if sub.Op >= opPseudo {
		parse.go#L296: 	for i > 0 && p.stack[i-1].Op < opPseudo {
		parse.go#L315: 	for i > 0 && p.stack[i-1].Op < opPseudo {
		regexp.go#L60: const opPseudo Op = 128 // where pseudo-ops start