Remove delegate/closure allocations from DynamicAssemblies.IsTypeDynamic (#66797)

Author: stephentoub

src/libraries/System.Private.Xml/src/System/Xml/Serialization/ContextAwareTables.cs

@@ -20,7 +20,7 @@ public ContextAwareTables()
             _collectibleTable = new ConditionalWeakTable<Type, T>();
         }
 
-        internal T GetOrCreateValue(Type t, Func<T> f)
+        internal T GetOrCreateValue(Type t, Func<Type, T> f)
         {
             // The fast and most common default case
             T? ret = (T?)_defaultTable[t];
@@ -41,7 +41,7 @@ internal T GetOrCreateValue(Type t, Func<T> f)
                 {
                     if ((ret = (T?)_defaultTable[t]) == null)
                     {
-                        ret = f();
+                        ret = f(t);
                         _defaultTable[t] = ret;
                     }
                 }
@@ -54,7 +54,7 @@ internal T GetOrCreateValue(Type t, Func<T> f)
                 {
                     if (!_collectibleTable.TryGetValue(t, out ret))
                     {
-                        ret = f();
+                        ret = f(t);
                         _collectibleTable.AddOrUpdate(t, ret);
                     }
                 }

src/libraries/System.Private.Xml/src/System/Xml/Serialization/ReflectionXmlSerializationReader.cs

@@ -639,7 +639,7 @@ private static ReflectionXmlSerializationReaderHelper.SetMemberValueDelegate Get
             Debug.Assert(o != null, "Object o should not be null");
             Debug.Assert(!string.IsNullOrEmpty(memberName), "memberName must have a value");
             Type type = o.GetType();
-            var delegateCacheForType = s_setMemberValueDelegateCache.GetOrCreateValue(type, () => new Hashtable());
+            var delegateCacheForType = s_setMemberValueDelegateCache.GetOrCreateValue(type, _ => new Hashtable());
             var result = delegateCacheForType[memberName];
             if (result == null)
             {

src/libraries/System.Private.Xml/src/System/Xml/Serialization/XmlSerializationWriter.cs

@@ -1466,7 +1466,7 @@ internal static class DynamicAssemblies
         // It's OK to suppress the SxS warning.
         internal static bool IsTypeDynamic(Type type)
         {
-            object oIsTypeDynamic = s_tableIsTypeDynamic.GetOrCreateValue(type, () =>
+            object oIsTypeDynamic = s_tableIsTypeDynamic.GetOrCreateValue(type, static type =>
             {
                 Assembly assembly = type.Assembly;
                 bool isTypeDynamic = assembly.IsDynamic /*|| string.IsNullOrEmpty(assembly.Location)*/;

src/libraries/System.Private.Xml/src/System/Xml/Serialization/XmlSerializer.cs

@@ -685,7 +685,7 @@ private static XmlSerializer[] GetSerializersFromCache(XmlMapping[] mappings, Ty
             Dictionary<XmlSerializerMappingKey, XmlSerializer>? typedMappingTable = null;
             AssemblyLoadContext? alc = AssemblyLoadContext.GetLoadContext(type.Assembly);
 
-            typedMappingTable = s_xmlSerializerTable.GetOrCreateValue(type, () => new Dictionary<XmlSerializerMappingKey, XmlSerializer>());
+            typedMappingTable = s_xmlSerializerTable.GetOrCreateValue(type, _ => new Dictionary<XmlSerializerMappingKey, XmlSerializer>());
 
             lock (typedMappingTable)
             {