C++: Introduce a new base class for template parameters

This will enable us to support non-type template parameters, which we
currently do not support, and error template parameters, which might
become relevant in the `build-mode: none` context.

cpp/ql/src/Best Practices/Unused Entities/UnusedLocals.ql

@@ -26,7 +26,7 @@ import cpp
  */
 class TemplateDependentType extends Type {
   TemplateDependentType() {
-    this instanceof TemplateParameter
+    this instanceof TypeTemplateParameter
     or
     exists(TemplateDependentType t |
       this.refersToDirectly(t) and

cpp/ql/src/Likely Bugs/Arithmetic/PointlessSelfComparison.qll

@@ -49,7 +49,7 @@ predicate nanTest(EqualityOperation cmp) {
   pointlessSelfComparison(cmp) and
   exists(Type t | t = cmp.getLeftOperand().getUnspecifiedType() |
     t instanceof FloatingPointType or
-    t instanceof TemplateParameter
+    t instanceof TypeTemplateParameter
   )
 }
 

cpp/ql/src/Likely Bugs/ReturnConstTypeCommon.qll

@@ -2,7 +2,7 @@ import cpp
 
 private predicate mightHaveConstMethods(Type t) {
   t instanceof Class or
-  t instanceof TemplateParameter
+  t instanceof TypeTemplateParameter
 }
 
 predicate hasSuperfluousConstReturn(Function f) {

cpp/ql/src/jsf/4.13 Functions/AV Rule 114.ql

@@ -26,7 +26,7 @@ predicate functionsMissingReturnStmt(Function f, ControlFlowNode blame) {
   exists(Type returnType |
     returnType = f.getUnspecifiedType() and
     not returnType instanceof VoidType and
-    not returnType instanceof TemplateParameter
+    not returnType instanceof TypeTemplateParameter
   ) and
   exists(ReturnStmt s |
     f.getAPredecessor() = s and