Improve detection of alignof availability
Improve detection of alignof availability

nodejs/nan,eljefedelrodeodeljefe/nan,eljefedelrodeodeljefe/nan,addaleax/nan,addaleax/nan,nodejs/nan,addaleax/nan,gagern/nan,nodejs/nan,addaleax/nan,eljefedelrodeodeljefe/nan,nodejs/nan,gagern/nan,eljefedelrodeodeljefe/nan,gagern/nan