Dataflow: Add dummy DataFlowSecondLevelScope implementations.

These could be an empty type, but Unit was available and it probably
doesn't matter.

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

@@ -286,6 +286,8 @@ predicate lambdaCall(DataFlowCall call, LambdaCallKind kind, Node receiver) { no
 /** Extra data-flow steps needed for lambda flow analysis. */
 predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preservesValue) { none() }
 
+class DataFlowSecondLevelScope = Unit;
+
 /**
  * Holds if flow is allowed to pass from parameter `p` and back to itself as a
  * side-effect, resulting in a summary from `p` to itself.

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

@@ -3013,6 +3013,8 @@ predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preserves
   preservesValue = true
 }
 
+class DataFlowSecondLevelScope = Unit;
+
 /**
  * Holds if flow is allowed to pass from parameter `p` and back to itself as a
  * side-effect, resulting in a summary from `p` to itself.

go/ql/lib/semmle/go/dataflow/internal/DataFlowPrivate.qll

@@ -412,6 +412,8 @@ predicate lambdaCall(DataFlowCall call, LambdaCallKind kind, Node receiver) { no
 /** Extra data-flow steps needed for lambda flow analysis. */
 predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preservesValue) { none() }
 
+class DataFlowSecondLevelScope = Unit;
+
 /**
  * Holds if flow is allowed to pass from parameter `p` and back to itself as a
  * side-effect, resulting in a summary from `p` to itself.

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

@@ -576,6 +576,8 @@ predicate lambdaCall(DataFlowCall call, LambdaCallKind kind, Node receiver) {
 /** Extra data-flow steps needed for lambda flow analysis. */
 predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preservesValue) { none() }
 
+class DataFlowSecondLevelScope = Unit;
+
 /**
  * Holds if flow is allowed to pass from parameter `p` and back to itself as a
  * side-effect, resulting in a summary from `p` to itself.

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

@@ -1057,6 +1057,8 @@ predicate lambdaCall(DataFlowCall call, LambdaCallKind kind, Node receiver) {
 /** Extra data-flow steps needed for lambda flow analysis. */
 predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preservesValue) { none() }
 
+class DataFlowSecondLevelScope = Unit;
+
 /**
  * Holds if flow is allowed to pass from parameter `p` and back to itself as a
  * side-effect, resulting in a summary from `p` to itself.

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowPrivate.qll

@@ -2174,6 +2174,8 @@ predicate lambdaCall(DataFlowCall call, LambdaCallKind kind, Node receiver) {
 /** Extra data-flow steps needed for lambda flow analysis. */
 predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preservesValue) { none() }
 
+class DataFlowSecondLevelScope = Unit;
+
 /**
  * Holds if flow is allowed to pass from parameter `p` and back to itself as a
  * side-effect, resulting in a summary from `p` to itself.

swift/ql/lib/codeql/swift/dataflow/internal/DataFlowPrivate.qll

@@ -1396,6 +1396,8 @@ predicate lambdaCall(DataFlowCall call, LambdaCallKind kind, Node receiver) {
 /** Extra data-flow steps needed for lambda flow analysis. */
 predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preservesValue) { none() }
 
+class DataFlowSecondLevelScope = Unit;
+
 /**
  * Holds if flow is allowed to pass from parameter `p` and back to itself as a
  * side-effect, resulting in a summary from `p` to itself.