added hashCode()

git-svn-id: file:///humgen/gsa-scr1/gsa-engineering/svn_contents/trunk@937 348d0f76-0448-11de-a6fe-93d51630548a

java/src/org/broadinstitute/sting/utils/GenomeLoc.java

@@ -481,6 +481,12 @@ public class GenomeLoc implements Comparable<GenomeLoc>, Cloneable {
         }
         return false;
     }
+    
+    @Override
+    public int hashCode() {
+        return (int)( start << 16 + stop << 4 + contigIndex );
+    }
+
 
     /**
      * Return a new GenomeLoc at this same position.