Few openers in recent memory set the tone of an album quite like Infinity Knives and Brian Ennals’ “The Iron Wall.” It’s immediately nerve-shredding, as producer Infinity Knives (né Tariq Ravelomanana) programs an atonal sequence and jittery drums that tumble over each other like a charging rock slide. When rapper Brian Ennals sneers “Yo” a second before his verse, it’s …