Simplify VarAccess.isLValue()

Author: Marcono1234

java/ql/src/semmle/code/java/Expr.qll

@@ -1344,10 +1344,7 @@ class VarAccess extends Expr, @varaccess {
    */
   predicate isLValue() {
     exists(Assignment a | a.getDest() = this) or
-    exists(PreIncExpr e | e.getExpr() = this) or
-    exists(PreDecExpr e | e.getExpr() = this) or
-    exists(PostIncExpr e | e.getExpr() = this) or
-    exists(PostDecExpr e | e.getExpr() = this)
+    exists(UnaryAssignExpr e | e.getExpr() = this)
   }
 
   /**