Data flow: Cache jumpStep

Author: hvitved

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll

@@ -234,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll

@@ -160,7 +160,7 @@ private module LambdaFlow {
       toJump = true and
       lastCall = TDataFlowCallNone()
     |
-      jumpStep(node, mid) and
+      jumpStepCached(node, mid) and
       t = t0
       or
       exists(boolean preservesValue |
@@ -253,6 +253,9 @@ private module Cached {
   cached
   predicate nodeDataFlowType(Node n, DataFlowType t) { t = getNodeType(n) }
 
+  cached
+  predicate jumpStepCached(Node node1, Node node2) { jumpStep(node1, node2) }
+
   /**
    * Gets a viable target for the lambda call `call`.
    *