Update new test diagnostics

Author: DougGregor

test/Concurrency/async_initializer.swift

@@ -103,18 +103,19 @@ enum E {
 }
 
 struct SomeStruct {
-  @MainActor init(asyncMainActor: Int) async {}
+  @MainActor init(asyncMainActor: Int) async {} // expected-note{{calls to initializer 'init(asyncMainActor:)' from outside of its actor context are implicitly asynchronous}}
   @MainActor init(mainActor: Int) {} // expected-note {{calls to initializer 'init(mainActor:)' from outside of its actor context are implicitly asynchronous}}
   @MainActor(unsafe) init(asyncMainActorUnsafe: Int) async {}
   @MainActor(unsafe) init(mainActorUnsafe: Int) {}
 }
 
-// expected-note@+2 {{add '@MainActor' to make global function 'globActorTest1()' part of global actor 'MainActor'}}
+// expected-note@+2 2{{add '@MainActor' to make global function 'globActorTest1()' part of global actor 'MainActor'}}
 // expected-note@+1 2 {{add 'async' to function 'globActorTest1()' to make it asynchronous}}
 func globActorTest1() {
   _ = SomeStruct(asyncMainActor: 0) // expected-error {{'async' call in a function that does not support concurrency}}
+  // expected-error@-1{{call to main actor-isolated initializer 'init(asyncMainActor:)' in a synchronous nonisolated context}}
 
-  _ = SomeStruct(mainActor: 0) // expected-error {{initializer 'init(mainActor:)' isolated to global actor 'MainActor' can not be referenced from this synchronous context}}
+  _ = SomeStruct(mainActor: 0) // expected-error {{call to main actor-isolated initializer 'init(mainActor:)' in a synchronous nonisolated context}}
 
   _ = SomeStruct(asyncMainActorUnsafe: 0) // expected-error {{'async' call in a function that does not support concurrency}}
 
@@ -162,4 +163,4 @@ protocol Spicy: Plain {
   // expected-error@+2 {{cannot override non-async initializer with async initializer}}
   // expected-error@+1 {{initializer does not override a designated initializer from its parent protocol}}
   override init() async
-}
+}