[cxx-interop] Update and enable libc++ module interface test

rdar://84036022

Author: egorzhdan

test/Interop/Cxx/stdlib/libcxx-module-interface.swift

@@ -5,27 +5,25 @@
 // This test is specific to libc++ and therefore only runs on Darwin platforms.
 // REQUIRES: OS=macosx || OS=ios
 
-// REQUIRES: rdar84036022
-
 // CHECK-STD: import std.iosfwd
 // CHECK-STD: import std.string
 
-// CHECK-IOSFWD: extension std.__1 {
-// CHECK-IOSFWD:   struct __CxxTemplateInstNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE {
-// CHECK-IOSFWD:     typealias value_type = CChar
-// CHECK-IOSFWD:   }
-// CHECK-IOSFWD:   struct __CxxTemplateInstNSt3__112basic_stringIwNS_11char_traitsIwEENS_9allocatorIwEEEE {
-// CHECK-IOSFWD:     typealias value_type = CWideChar
+// CHECK-IOSFWD: enum std {
+// CHECK-IOSFWD:   enum __1 {
+// CHECK-IOSFWD:     struct __CxxTemplateInstNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE {
+// CHECK-IOSFWD:       typealias value_type = CChar
+// CHECK-IOSFWD:     }
+// CHECK-IOSFWD:     struct __CxxTemplateInstNSt3__112basic_stringIwNS_11char_traitsIwEENS_9allocatorIwEEEE {
+// CHECK-IOSFWD:       typealias value_type = CWideChar
+// CHECK-IOSFWD:     }
+// CHECK-IOSFWD:     typealias string = std.__1.__CxxTemplateInstNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE
+// CHECK-IOSFWD:     typealias wstring = std.__1.__CxxTemplateInstNSt3__112basic_stringIwNS_11char_traitsIwEENS_9allocatorIwEEEE
 // CHECK-IOSFWD:   }
-// CHECK-IOSFWD:   typealias string = std.__1.__CxxTemplateInstNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE
-// CHECK-IOSFWD:   typealias wstring = std.__1.__CxxTemplateInstNSt3__112basic_stringIwNS_11char_traitsIwEENS_9allocatorIwEEEE
 // CHECK-IOSFWD: }
 
-// CHECK-STRING: extension std.__1 {
-// CHECK-STRING:   static func to_string(_ __val: Int32) -> std.__1.string
-// CHECK-STRING:   static func to_wstring(_ __val: Int32) -> std.__1.wstring
+// CHECK-STRING: enum std {
+// CHECK-STRING:   enum __1 {
+// CHECK-STRING:     static func to_string(_ __val: Int32) -> std.__1.string
+// CHECK-STRING:     static func to_wstring(_ __val: Int32) -> std.__1.wstring
+// CHECK-STRING:   }
 // CHECK-STRING: }
-
-// CHECK-IOSFWD-NOT: static func to_string
-// CHECK-STRING-NOT: typealias string
-// CHECK-STD-NOT: extension std