Method traceCtrl

chapter21/src/test/java/com/seaofnodes/simple/Eval2.java:379–384

( CFGNode BB, SB sb )

    static void traceCtrl( CFGNode BB, SB sb ) {
        if( sb==null ) return;
        IRPrinter.printLine(BB,sb.p("--- "));
        System.out.print(sb);
        sb.clear();
    }
    static void traceData( Node n, SB sb ) {
        if( sb==null ) return;
        IRPrinter.printLine(n,sb).unchar();