helper method for string += operation

git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@200 379699f6-c40d-0410-875b-85095c16579e

jode/jode/expr/StringAddOperator.java

@@ -28,6 +28,10 @@ public class StringAddOperator extends SimpleOperator {
         operandTypes[1] = Type.tUnknown;
     }
 
+    public void clearFirstType() {
+	operandTypes[0] = Type.tUnknown;
+    }
+    
     public int getPriority() {
         return 610;
     }