Just to add some JS engine info - every engine stores numbers as 32 bit integers if possible, which is usually done by tagging a pointer. Also, JSC needs pointe

Just to add some JS engine info - every engine stores numbers as 32 bit integers if possible, which is usually done by tagging a pointer. Also, JSC needs pointers to be represented exactly as-is, because it will scan the stack for anything that looks like a pointer, and retain it when running the GC