Python: Add call-graph to cached dataflow stage

I didn't do any performance investigation on this, since it just seems
so much like the right approach.

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowDispatch.qll

@@ -37,6 +37,7 @@ private import DataFlowPublic
 private import DataFlowPrivate
 private import FlowSummaryImpl as FlowSummaryImpl
 private import FlowSummaryImplSpecific as FlowSummaryImplSpecific
+private import semmle.python.internal.CachedStages
 
 newtype TParameterPosition =
   /** Used for `self` in methods, and `cls` in classmethods. */
@@ -1041,6 +1042,8 @@ predicate resolveClassInstanceCall(CallNode call, Function target, Node self) {
  */
 cached
 predicate resolveCall(ControlFlowNode call, Function target, CallType type) {
+  Stages::DataFlow::ref() and
+  (
     type instanceof CallTypePlainFunction and
     call.(CallNode).getFunction() = functionTracker(target).asCfgNode() and
     not exists(Class cls | cls.getAMethod() = target)
@@ -1055,6 +1058,7 @@ predicate resolveCall(ControlFlowNode call, Function target, CallType type) {
     or
     type instanceof CallTypeClassInstanceCall and
     resolveClassInstanceCall(call, target, _)
+  )
 }
 
 // =============================================================================
@@ -1119,6 +1123,8 @@ cached
 predicate getCallArg(
   ControlFlowNode call, Function target, CallType type, Node arg, ArgumentPosition apos
 ) {
+  Stages::DataFlow::ref() and
+  (
     // normal calls with a real call node
     resolveCall(call, target, type) and
     call instanceof CallNode and
@@ -1192,6 +1198,7 @@ predicate getCallArg(
         normalCallArg(call, arg, apos)
       )
     )
+  )
 }
 
 // =============================================================================

python/ql/lib/semmle/python/internal/CachedStages.qll

@@ -180,6 +180,7 @@ module Stages {
     predicate ref() { 1 = 1 }
 
     private import semmle.python.dataflow.new.internal.DataFlowPublic as DataFlowPublic
+    private import semmle.python.dataflow.new.internal.DataFlowDispatch as DataFlowDispatch
     private import semmle.python.dataflow.new.internal.LocalSources as LocalSources
     private import semmle.python.internal.Awaited as Awaited
 
@@ -195,6 +196,10 @@ module Stages {
       or
       any(DataFlowPublic::Node node).hasLocationInfo(_, _, _, _, _)
       or
+      DataFlowDispatch::resolveCall(_, _, _)
+      or
+      DataFlowDispatch::getCallArg(_, _, _, _, _)
+      or
       any(LocalSources::LocalSourceNode n).flowsTo(_)
       or
       exists(Awaited::awaited(_))