Fixed a bug in computing isolation of @objc actors. Added tests for @objc declarations

Author: nickolas-pohilets

lib/Sema/TypeCheckConcurrency.cpp

@@ -5089,7 +5089,9 @@ ActorIsolation ActorIsolationRequest::evaluate(
     ActorIsolation isolation = ActorIsolation::forUnspecified();
     if (overriddenValue) {
       isolation = getOverriddenIsolationFor(value);
-    } else if (hasIsolatedSelf) {
+    }
+
+    if (hasIsolatedSelf && isolation.isUnspecified()) {
       // Don't use 'unspecified' for actors, use 'nonisolated' instead
       // To force generation of the 'nonisolated' attribute in SIL and
       // .swiftmodule

test/Concurrency/deinit_isolation.swift

@@ -2,6 +2,8 @@
 // RUN: %target-swift-frontend -parse-as-library -emit-silgen -DSILGEN %s | %FileCheck %s
 // RUN: %target-swift-frontend -parse-as-library -emit-silgen -DSILGEN %s | %FileCheck -check-prefix=CHECK-SYMB %s
 
+// REQUIRES: concurrency
+
 // Fixtures
 
 @globalActor final actor FirstActor {
@@ -52,9 +54,7 @@ class BaseWithDeinitIsolatedOnSecondActor {
     @SecondActor deinit {} // expected-note 2{{overridden declaration is here}}
 }
 
-//
-// Part 1 - Actors
-//
+// MARK: - Part 1 - Actors
 
 // CHECK-LABEL: actor ImplicitDeinitActor {
 // CHECK: @objc nonisolated deinit
@@ -119,8 +119,8 @@ actor IsolatedDeinitActor {
     }
 }
 
-// Part 2 - Classes
-// Part 2.1 - Without base class
+// MARK: - Part 2 - Classes
+// MARK: - Part 2.1 - Without base class
 
 // CHECK-LABEL: @FirstActor class ImplicitDeinit {
 // CHECK: @objc deinit
@@ -205,7 +205,7 @@ class DifferentIsolatedDeinit {
     }
 }
 
-// Part 2.2 - Base class with nonisolated deinit
+// MARK: - Part 2.2 - Base class with nonisolated deinit
 
 // CHECK-LABEL: @_inheritsConvenienceInitializers @FirstActor class ImplicitDeinitInheritNonisolated : BaseWithNonisolatedDeinit {
 // CHECK: @objc deinit
@@ -290,7 +290,7 @@ class DifferentIsolatedDeinitInheritNonisolated: BaseWithNonisolatedDeinit {
     }
 }
 
-// Part 2.3 - Base class with isolated deinit
+// MARK: - Part 2.3 - Base class with isolated deinit
 
 // CHECK-LABEL: @_inheritsConvenienceInitializers @FirstActor class ImplicitDeinitInheritIsolated1 : BaseWithDeinitIsolatedOnFirstActor {
 // CHECK:   @objc @FirstActor deinit
@@ -359,7 +359,7 @@ class DifferentIsolatedDeinitIsolated1: BaseWithDeinitIsolatedOnFirstActor {
 }
 #endif
 
-// Part 2.4 - Base class with isolated deinit with different actor
+// MARK: - Part 2.4 - Base class with isolated deinit with different actor
 
 // CHECK-LABEL: @_inheritsConvenienceInitializers @FirstActor class ImplicitDeinitInheritIsolated2 : BaseWithDeinitIsolatedOnSecondActor {
 // CHECK:   @objc @SecondActor deinit