Python: Remove cartesian product in TKwOverflowNode

With CP:

(0s) Tuple counts for dom#DataFlowPublic::TKwOverflowNode#ff:
1209    ~0%       {2} r1 = JOIN project#AstGenerated::Function_::getKwarg_dispred#ff AS L WITH ObjectAPI::CallableValue::getScope_dispred#ff_10#join_rhs AS R ON FIRST 1 OUTPUT R.<1>, L.<0>
4329    ~0%       {3} r2 = JOIN r1 WITH DataFlowPrivate::ArgumentPassing::connects#bb_10#join_rhs AS R ON FIRST 1 OUTPUT R.<1>, r1.<1>, r1.<0>
7819    ~2%       {4} r3 = JOIN r2 WITH Flow::CallNode::getArgByName_dispred#fff AS R ON FIRST 1 OUTPUT r2.<1>, r2.<2>, r2.<0>, R.<1>
7114    ~1%       {4} r4 = r3 AND NOT Function::Function::getArgByName_dispred#fff_01#antijoin_rhs AS R(r3.<0>, r3.<3>)
7114    ~76%      {2} r5 = SCAN r4 OUTPUT r4.<2>, r4.<1>
1123    ~0%       {1} r6 = JOIN project#Exprs::Call::getKwargs_dispred#ff AS L WITH py_flow_bb_node_10#join_rhs AS R ON FIRST 1 OUTPUT R.<1>
1123    ~0%       {1} r7 = JOIN r6 WITH Flow::CallNode#class#f AS R ON FIRST 1 OUTPUT r6.<0>
1357707 ~0%       {2} r8 = JOIN r7 WITH project#AstGenerated::Function_::getKwarg_dispred#ff AS R CARTESIAN PRODUCT OUTPUT R.<0>, r7.<0>
1357707 ~0%       {2} r9 = JOIN r8 WITH ObjectAPI::CallableValue::getScope_dispred#ff_10#join_rhs AS R ON FIRST 1 OUTPUT r8.<1>, R.<1>
1364821 ~0%       {2} r10 = r5 \/ r9
                  return r10

Without CP:

(13s) Tuple counts for dom#DataFlowPublic::TKwOverflowNode#ff:
1209    ~0%       {2} r1 = JOIN project#AstGenerated::Function_::getKwarg_dispred#ff AS L WITH ObjectAPI::CallableValue::getScope_dispred#ff_10#join_rhs AS R ON FIRST 1 OUTPUT R.<1>, L.<0>
19175   ~4%       {3} r2 = JOIN r1 WITH DataFlowPrivate::ArgumentPassing::connects#ff_10#join_rhs AS R ON FIRST 1 OUTPUT R.<1>, r1.<1>, r1.<0>
7819    ~2%       {4} r3 = JOIN r2 WITH Flow::CallNode::getArgByName_dispred#fff AS R ON FIRST 1 OUTPUT r2.<1>, r2.<2>, r2.<0>, R.<1>
7114    ~1%       {4} r4 = r3 AND NOT Function::Function::getArgByName_dispred#fff_01#antijoin_rhs AS R(r3.<0>, r3.<3>)
7114    ~76%      {2} r5 = SCAN r4 OUTPUT r4.<2>, r4.<1>
1123    ~0%       {1} r6 = JOIN project#Exprs::Call::getKwargs_dispred#ff AS L WITH py_flow_bb_node_10#join_rhs AS R ON FIRST 1 OUTPUT R.<1>
574     ~0%       {2} r7 = JOIN r6 WITH DataFlowPrivate::ArgumentPassing::connects#ff AS R ON FIRST 1 OUTPUT R.<1>, r6.<0>
524     ~1%       {3} r8 = JOIN r7 WITH ObjectAPI::CallableValue::getScope_dispred#ff AS R ON FIRST 1 OUTPUT R.<1>, r7.<1>, r7.<0>
291     ~0%       {2} r9 = JOIN r8 WITH project#AstGenerated::Function_::getKwarg_dispred#ff AS R ON FIRST 1 OUTPUT r8.<1>, r8.<2>
7405    ~72%      {2} r10 = r5 \/ r9
                  return r10

Author: tausbn

python/ql/src/experimental/dataflow/internal/DataFlowPrivate.qll

@@ -292,7 +292,7 @@ private Node update(Node node) {
  * `y`. There is a dataflow step from `**{"y": 1, "a": 3}` to `[**d]` to transfer the content and
  * a clearing of content at key `y` for node `[**d]`, since that value has been unpacked.
  */
-private module ArgumentPassing {
+module ArgumentPassing {
   /**
    * Holds if `call` represents a `DataFlowCall` to a `DataFlowCallable` represented by `callable`.
    *

python/ql/src/experimental/dataflow/internal/DataFlowPublic.qll

@@ -49,6 +49,7 @@ newtype TNode =
   TKwOverflowNode(CallNode call, CallableValue callable) {
     exists(getKeywordOverflowArg(call, callable, _))
     or
+    ArgumentPassing::connects(call, callable) and
     exists(call.getNode().getKwargs()) and
     callable.getScope().hasKwArg()
   } or