Java: Perf fix.

Author: aschackmull

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowPrivate.qll

@@ -120,6 +120,9 @@ module ExceptionFlow {
     not tryCatch(_, s1)
   }
 
+  pragma[nomagic]
+  private Callable excReturnGetCallable(ExceptionReturnNode n) { result = n.getEnclosingCallable() }
+
   /** Holds if a thrown exception can flow locally from `node1` to `node2`. */
   predicate localStep(Node node1, Node node2) {
     exists(Stmt exc |
@@ -135,7 +138,7 @@ module ExceptionFlow {
       or
       exists(Callable callable |
         excStep+(exc, callable.getBody()) and
-        node2.(ExceptionReturnNode).getEnclosingCallable() = callable
+        excReturnGetCallable(node2) = callable
       )
     )
     or