[Property wrappers] Expand testing for backing initializer linkage change.

Author: DougGregor

test/SILGen/property_wrappers_library_evolution.swift

@@ -1,10 +1,19 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-swift-frontend -emit-module -o %t -enable-library-evolution %S/Inputs/property_wrapper_defs.swift
-// RUN: %target-swift-emit-silgen -primary-file %s -I %t -enable-library-evolution
+// RUN: %target-swift-emit-silgen -primary-file %s -I %t -enable-library-evolution | %FileCheck %s
 import property_wrapper_defs
 
 // rdar://problem/55995892
 // This is a crash that occurs only with -enable-library-evolution.
 
 public enum E { case a }
 struct M { @MyPublished private var e = E.a }
+
+// Ensure that the backing initializer is serialized.
+@frozen
+public struct StructUsesPublishedAsPrivate {
+  public var integer: Int = 17
+
+  // CHECK: sil non_abi [serialized] [ossa] @$s35property_wrappers_library_evolution28StructUsesPublishedAsPrivateV6stringSSvpfP : $@convention(thin) (@owned String) -> @out MyPublished<String>
+  @MyPublished var string: String = "Hello"
+}

test/decl/var/property_wrappers_library_evolution.swift

@@ -0,0 +1,20 @@
+// RUN: %target-swift-frontend -typecheck %s -verify -enable-library-evolution
+
+@propertyWrapper
+public struct ResilientWrapper<T> {
+  public var wrappedValue: T
+
+  public init(wrappedValue: T, description: String) {
+    self.wrappedValue = wrappedValue
+  }
+}
+
+func getHello() -> String { return "hello" } // expected-note 2 {{global function 'getHello()' is not '@usableFromInline' or public}}
+
+@frozen
+public struct StructUsesPublishedAsPrivate {
+  public var integer: Int = 17
+
+  @ResilientWrapper(description: getHello()) // expected-error 2 {{global function 'getHello()' is internal and cannot be referenced from a property initializer in a '@frozen' type}}
+  var otherString: String = "World"
+}