[Distributed] make sure resolvable works with package level access (#80080)

Author: ktoso

test/Distributed/Macros/distributed_macro_expansion_DistributedProtocol_package_access.swift

@@ -0,0 +1,36 @@
+// REQUIRES: swift_swift_parser, asserts
+//
+// UNSUPPORTED: back_deploy_concurrency
+// REQUIRES: concurrency
+// REQUIRES: distributed
+//
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t-scratch)
+
+// RUN: %target-swift-frontend -typecheck -verify -target %target-swift-6.0-abi-triple -package-name myPkg -plugin-path %swift-plugin-dir -I %t -dump-macro-expansions %s -dump-macro-expansions 2>&1 | %FileCheck %s
+
+import Distributed
+
+@Resolvable
+package protocol Greeter: DistributedActor where ActorSystem: DistributedActorSystem<any Codable> {
+  distributed func greet(name: String) -> String
+}
+
+// @Resolvable ->
+
+// CHECK: package distributed actor $Greeter<ActorSystem>: Greeter,
+// CHECK-NEXT: Distributed._DistributedActorStub
+// CHECK-NEXT: where ActorSystem: DistributedActorSystem<any Codable>
+// CHECK-NEXT: {
+// CHECK: }
+
+// CHECK: extension Greeter where Self: Distributed._DistributedActorStub {
+// CHECK:   package distributed func greet(name: String) -> String {
+// CHECK-NEXT:     if #available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *) {
+// CHECK-NEXT:       Distributed._distributedStubFatalError()
+// CHECK-NEXT:     } else {
+// CHECK-NEXT:       fatalError()
+// CHECK-NEXT:     }
+// CHECK-NEXT:   }
+// CHECK-NEXT: }
+