“Hanging’s too good for ’em. Cos it is. Int it?” offers Bill, one of a trio of half-sozzled regulars that pontificate over a pint, or several, along with idle police inspector Fry. On one hand, McDonagh is having fun with the freedom of pre-PC England to air his characters’ unapologetic prejudices without inhibition — Northern Brits take the most flak, but black immigrants, Americans, the French, the Scots and particularly the Germans all are targets of droll swipes. On the other hand, the mid-’60s time frame allows the playwright to depict a climate of rigid moral superiority, where people are unaccustomed to having their conservative values questioned. “Sacrosanct” is a word that pops up repeatedly, and McDonagh takes devious pleasure in piercing the inviolate bubble of his characters.