question: boolean eliminate ( ) { boolean change = false ; Instruction prev = first ; for ( Instruction inst = first . next ; inst != null ; inst = inst . next ) { if ( inst . pc != NOTREACHED ) { prev . next = inst ; prev = inst ; inst . pc = NOTREACHED ; } else { change = true ; } } first . pc = NOTREACHED ; prev . next = null ; return change ; }
target:  Eliminate instructions that are not reached