add FlexibleTypeCapabilitiesDeserializer.Dynamic object

core/serialization/src/org/jetbrains/kotlin/serialization/deserialization/FlexibleTypeCapabilitiesDeserializer.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.serialization.deserialization
 
+import org.jetbrains.kotlin.types.DynamicTypeCapabilities
 import org.jetbrains.kotlin.types.FlexibleTypeCapabilities
 
 trait FlexibleTypeCapabilitiesDeserializer {
@@ -25,5 +26,12 @@ trait FlexibleTypeCapabilitiesDeserializer {
         }
     }
 
+    object Dynamic : FlexibleTypeCapabilitiesDeserializer {
+        override fun capabilitiesById(id: String): FlexibleTypeCapabilities? {
+            return if (id == DynamicTypeCapabilities.id) DynamicTypeCapabilities else null
+        }
+    }
+
+
     fun capabilitiesById(id: String): FlexibleTypeCapabilities?
 }