const regexp/syntax.opLeftParen

5 uses

	regexp/syntax (current package)
		parse.go#L75: 	opLeftParen = opPseudo + iota
		parse.go#L734: 			p.op(opLeftParen).Cap = p.numCap
		parse.go#L980: 		re := p.op(opLeftParen)
		parse.go#L1036: 				p.op(opLeftParen)
		parse.go#L1219: 	if re2.Op != opLeftParen {