[Tests] NFC: Re-enable rdar://57201781 and rdar://70880670

A crash that was causing these tests to fail has been resolved.

Author: xedin

validation-test/Sema/SwiftUI/rdar57201781.swift

@@ -3,7 +3,7 @@
 // REQUIRES: objc_interop
 // REQUIRES: OS=macosx
 // https://github.com/swiftlang/swift/issues/79255
-// REQUIRES: rdar141262107
+
 import SwiftUI
 
 struct ContentView : View {

validation-test/Sema/SwiftUI/rdar70880670.swift

@@ -2,7 +2,7 @@
 // REQUIRES: objc_interop
 // REQUIRES: OS=macosx
 // https://github.com/swiftlang/swift/issues/79255
-// REQUIRES: rdar141262107
+
 import SwiftUI
 
 var foo = doesntExist // expected-error {{cannot find 'doesntExist' in scope}}