avoid a ValueNode x TypeTracker join in Hapi::RouteSetup::getARouteHandler

Author: erik-krogh

javascript/ql/src/semmle/javascript/frameworks/Hapi.qll

@@ -196,11 +196,14 @@ module Hapi {
 
     private DataFlow::SourceNode getARouteHandler(DataFlow::TypeBackTracker t) {
       t.start() and
-      result = handler.flow().getALocalSource()
+      result = getRouteHandler().getALocalSource()
       or
       exists(DataFlow::TypeBackTracker t2 | result = getARouteHandler(t2).backtrack(t2, t))
     }
 
+    pragma[noinline]
+    private DataFlow::Node getRouteHandler() { result = handler.flow() }
+
     Expr getRouteHandlerExpr() { result = handler }
 
     override Expr getServer() { result = server }