A few bits of java code which use "" + x and can't be helped

out by scala compiler optimizations.  No review.

git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@24013 5e8d7ff9-d8ef-0310-90f0-a4852d11357a

src/fjbg/ch/epfl/lamp/fjbg/JStackMapTableAttribute.java

@@ -144,7 +144,7 @@ public class JStackMapTableAttribute extends JAttribute {
             case 8: // ITEM_Uninitialized
                 return "<uninitialized>";
             default:
-                return ""+tag;
+                return String.valueOf(tag);
             }
         }
     }

src/fjbg/ch/epfl/lamp/fjbg/JType.java

@@ -310,7 +310,7 @@ abstract public class JType {
         case T_OBJECT  : return "Object";
         case T_UNKNOWN : return "<unknown>";
         case T_ADDRESS : return "<address>";
-        default:         return ""+tag;
+        default:         return String.valueOf(tag);
         }
     }
 }

src/library/scala/runtime/BooleanRef.java

@@ -16,5 +16,5 @@ public class BooleanRef implements java.io.Serializable {
 
     public boolean elem;
     public BooleanRef(boolean elem) { this.elem = elem; }
-    public String toString() { return "" + elem; }
+    public String toString() { return String.valueOf(elem); }
 }

src/library/scala/runtime/ObjectRef.java

@@ -16,5 +16,5 @@ public class ObjectRef implements java.io.Serializable {
 
     public Object elem;
     public ObjectRef(Object elem) { this.elem = elem; }
-    public String toString() { return "" + elem; }
+    public String toString() { return String.valueOf(elem); }
 }

src/library/scala/runtime/VolatileBooleanRef.java

@@ -16,5 +16,5 @@ public class VolatileBooleanRef implements java.io.Serializable {
     
     volatile public boolean elem;
     public VolatileBooleanRef(boolean elem) { this.elem = elem; }
-    public String toString() { return "" + elem; }
+    public String toString() { return String.valueOf(elem); }
 }

src/library/scala/runtime/VolatileObjectRef.java

@@ -16,5 +16,5 @@ public class VolatileObjectRef implements java.io.Serializable {
 
     volatile public Object elem;
     public VolatileObjectRef(Object elem) { this.elem = elem; }
-    public String toString() { return "" + elem; }
+    public String toString() { return String.valueOf(elem); }
 }