Go: Refactor SummarizedCallable.

 Equivalent of #9210

Author: owen-mc

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

@@ -12,7 +12,7 @@ private newtype TNode =
   MkGlobalFunctionNode(Function f) or
   MkSummarizedParameterNode(DataFlowCallable c, int i) {
     not exists(c.getFuncDef()) and
-    c instanceof SummarizedCallable and
+    c.asCallable() instanceof SummarizedCallable and
     (
       i in [0 .. c.getType().getNumParameter() - 1]
       or
@@ -115,7 +115,7 @@ module Public {
       exists(DataFlowCallable dfc | result = dfc.asCallable() |
         this = MkSummarizedParameterNode(dfc, _)
         or
-        this = MkSummaryInternalNode(dfc, _)
+        this = MkSummaryInternalNode(dfc.asCallable(), _)
       )
     }
 

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

@@ -14,6 +14,10 @@ private module FlowSummaries {
   private import semmle.go.dataflow.FlowSummary as F
 }
 
+class SummarizedCallableBase = Callable;
+
+DataFlowCallable inject(SummarizedCallable c) { result.asCallable() = c }
+
 /** Holds if `i` is a valid parameter position. */
 predicate parameterPosition(int i) {
   i = [-1 .. any(DataFlowCallable c).getType().getNumParameter()]
@@ -87,7 +91,7 @@ DataFlowType getCallbackReturnType(DataFlowType t, ReturnKind rk) { none() }
  * `input`, output specification `output`, kind `kind`, and a flag `generated`
  * stating whether the summary is autogenerated.
  */
-predicate summaryElement(DataFlowCallable c, string input, string output, string kind, boolean generated) {
+predicate summaryElement(Callable c, string input, string output, string kind, boolean generated) {
   exists(
     string namespace, string type, boolean subtypes, string name, string signature, string ext
   |