Apply division optimization to CharSet and IntSet as well

src/main/java/org/sablecc/sablecc/CharSet.java

@@ -47,7 +47,7 @@ public class CharSet implements Cloneable
 
     while(high >= low)
     {
-      int middle = (high + low) / 2;
+      int middle = (high + low) >>> 1;
 
       interval2 = (Interval) intervals.elementAt(middle);
 

src/main/java/org/sablecc/sablecc/IntSet.java

@@ -125,7 +125,7 @@ public class IntSet
 
     while(low <= high)
     {
-      int middle = (low + high) / 2;
+      int middle = (low + high) >>> 1;
 
       if(bit < elements[middle])
       {