C++: Reduce re-evaluation

cpp/ql/lib/semmle/code/cpp/dataflow/ExternalFlow.qll

@@ -555,6 +555,7 @@ private Locatable getSupportedFunctionTemplateArgument(Function templateFunction
  * Normalize the `n`'th parameter of `f` by replacing template names
  * with `func:N` (where `N` is the index of the template).
  */
+pragma[nomagic]
 private string getTypeNameWithoutFunctionTemplates(Function f, int n, int remaining) {
   exists(Function templateFunction |
     templateFunction = getFullyTemplatedFunction(f) and

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

@@ -201,7 +201,7 @@ module SourceSinkInterpretationInput implements
     string toString() {
       result = this.asElement().toString()
       or
-      result = this.asNode().toString()
+      result = this.asNode().toStringImpl()
       or
       result = this.asCall().toString()
     }