Minor. Pull user-data related things to CallableDescriptor

Currently, we assume user data for all non-FunctionDescriptor
declarations is empty

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

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.serialization.deserialization
 
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.metadata.ProtoBuf
 import org.jetbrains.kotlin.metadata.deserialization.TypeTable
@@ -26,7 +27,7 @@ interface ContractDeserializer {
         ownerFunction: FunctionDescriptor,
         typeTable: TypeTable,
         typeDeserializer: TypeDeserializer
-    ): Pair<FunctionDescriptor.UserDataKey<*>, ContractProvider>?
+    ): Pair<CallableDescriptor.UserDataKey<*>, ContractProvider>?
 
     companion object {
         val DEFAULT = object : ContractDeserializer {
@@ -35,7 +36,7 @@ interface ContractDeserializer {
                 ownerFunction: FunctionDescriptor,
                 typeTable: TypeTable,
                 typeDeserializer: TypeDeserializer
-            ): Pair<FunctionDescriptor.UserDataKey<*>, Nothing>? = null
+            ): Pair<CallableDescriptor.UserDataKey<*>, Nothing>? = null
         }
     }
 }

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

@@ -179,7 +179,7 @@ class MemberDeserializer(private val c: DeserializationContext) {
         unsubstitutedReturnType: KotlinType?,
         modality: Modality?,
         visibility: Visibility,
-        userDataMap: Map<out FunctionDescriptor.UserDataKey<*>, *>,
+        userDataMap: Map<out CallableDescriptor.UserDataKey<*>, *>,
         isSuspend: Boolean
     ) {
         initialize(
@@ -284,7 +284,7 @@ class MemberDeserializer(private val c: DeserializationContext) {
             local.typeDeserializer.type(proto.returnType(c.typeTable)),
             ProtoEnumFlags.modality(Flags.MODALITY.get(flags)),
             ProtoEnumFlags.visibility(Flags.VISIBILITY.get(flags)),
-            emptyMap<FunctionDescriptor.UserDataKey<*>, Any?>(),
+            emptyMap<CallableDescriptor.UserDataKey<*>, Any?>(),
             Flags.IS_SUSPEND.get(flags)
         )
         function.isOperator = Flags.IS_OPERATOR.get(flags)

core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedMemberDescriptor.kt

@@ -83,7 +83,7 @@ class DeserializedSimpleFunctionDescriptor(
         unsubstitutedReturnType: KotlinType?,
         modality: Modality?,
         visibility: Visibility,
-        userDataMap: Map<out FunctionDescriptor.UserDataKey<*>, *>,
+        userDataMap: Map<out CallableDescriptor.UserDataKey<*>, *>,
         isExperimentalCoroutineInReleaseEnvironment: DeserializedMemberDescriptor.CoroutinesCompatibilityMode
     ): SimpleFunctionDescriptorImpl {
         return super.initialize(