C#: The model generator should consider System.Type and System.DateTime as sanitizers.

Author: michaelnebel

csharp/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll

@@ -168,6 +168,8 @@ private predicate irrelevantCollectionType(CS::Type ct) {
 predicate isRelevantType(CS::Type t) {
   not t instanceof CS::SimpleType and
   not t instanceof CS::Enum and
+  not t instanceof SystemDateTimeStruct and
+  not t instanceof SystemTypeClass and
   not irrelevantCollectionType(t)
 }
 

csharp/ql/test/utils/modelgenerator/dataflow/Summaries.cs

@@ -431,13 +431,13 @@ public Int32 M4(Int32 i)
         return i;
     }
 
-    // SPURIOUS-summary=Models;SimpleTypes;false;M5;(System.DateTime);;Argument[0];ReturnValue;taint;df-generated
+    // neutral=Models;SimpleTypes;M5;(System.DateTime);summary;df-generated
     public DateTime M5(DateTime d)
     {
         return d;
     }
 
-    // SPURIOUS-summary=Models;SimpleTypes;false;M6;(System.Type);;Argument[0];ReturnValue;taint;df-generated
+    // neutral=Models;SimpleTypes;M6;(System.Type);summary;df-generated
     public Type M6(Type t)
     {
         return t;