Dataflow: Add support for C#/Python/Ruby/Swift.

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

@@ -1003,6 +1003,8 @@ predicate jumpStep(Node pred, Node succ) {
     succ.(SsaDefinitionNode).getDefinition())
   or
   succ.asExpr().getExpr().(ConstantReadAccess).getValue() = pred.asExpr().getExpr()
+  or
+  FlowSummaryImpl::Private::Steps::summaryJumpStep(pred, succ)
 }
 
 private ContentSet getKeywordContent(string name) {

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

@@ -44,6 +44,9 @@ DataFlowType getCallbackParameterType(DataFlowType t, ArgumentPosition pos) { an
  */
 DataFlowType getCallbackReturnType(DataFlowType t, ReturnKind rk) { any() }
 
+/** Gets the type of synthetic global `sg`. */
+DataFlowType getSyntheticGlobalType(SummaryComponent::SyntheticGlobal sg) { any() }
+
 /**
  * Holds if an external flow summary exists for `c` with input specification
  * `input`, output specification `output`, kind `kind`, and a flag `generated`