ConformanceChecker: Make actor_isolated_witness call out the protocol

Author: AnthonyLatsis

include/swift/AST/DiagnosticsSema.def

@@ -5659,9 +5659,10 @@ NOTE(shared_state_make_immutable,none,
 NOTE(shared_state_nonisolated_unsafe,none,
      "disable concurrency-safety checks if accesses are protected by an external synchronization mechanism", (const ValueDecl *))
 ERROR(actor_isolated_witness,none,
-     "%select{|distributed }0%1 %kind2 cannot be used to satisfy %3 protocol "
-     "requirement",
-     (bool, ActorIsolation, const ValueDecl *, ActorIsolation))
+     "%select{|distributed }0%1 %kind2 cannot be used to satisfy %3 "
+     "requirement from protocol %base4",
+     (bool, ActorIsolation, const ValueDecl *, ActorIsolation,
+      const ValueDecl *))
 ERROR(actor_cannot_conform_to_global_actor_protocol,none,
       "actor %0 cannot conform to global actor isolated protocol %1",
       (Type, Type))

lib/Sema/TypeCheckProtocol.cpp

@@ -3444,10 +3444,12 @@ ConformanceChecker::checkActorIsolation(ValueDecl *requirement,
 
   // Complain that this witness cannot conform to the requirement due to
   // actor isolation.
-  witness->diagnose(diag::actor_isolated_witness,
-                    isDistributed && !isDistributedDecl(witness),
-                    refResult.isolation, witness, requirementIsolation)
-    .limitBehaviorUntilSwiftVersion(behavior, 6);
+  witness
+      ->diagnose(diag::actor_isolated_witness,
+                 isDistributed && !isDistributedDecl(witness),
+                 refResult.isolation, witness, requirementIsolation,
+                 Conformance->getProtocol())
+      .limitBehaviorUntilSwiftVersion(behavior, 6);
 
   // If we need 'distributed' on the witness, add it.
   if (missingOptions.contains(MissingFlags::WitnessDistributed)) {