[Concurrency] Split @objc checking into a separate test file.

Author: DougGregor

test/attr/attr_objc.swift

@@ -1,6 +1,6 @@
-// RUN: %target-swift-frontend -disable-objc-attr-requires-foundation-module -typecheck -verify -verify-ignore-unknown %s -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference -enable-experimental-concurrency
-// RUN: %target-swift-ide-test -skip-deinit=false -print-ast-typechecked -source-filename %s -function-definitions=true -prefer-type-repr=false -print-implicit-attrs=true -explode-pattern-binding-decls=true -disable-objc-attr-requires-foundation-module -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference -enable-experimental-concurrency | %FileCheck %s
-// RUN: not %target-swift-frontend -typecheck -dump-ast -disable-objc-attr-requires-foundation-module %s -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference -enable-experimental-concurrency > %t.ast
+// RUN: %target-swift-frontend -disable-objc-attr-requires-foundation-module -typecheck -verify -verify-ignore-unknown %s -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference
+// RUN: %target-swift-ide-test -skip-deinit=false -print-ast-typechecked -source-filename %s -function-definitions=true -prefer-type-repr=false -print-implicit-attrs=true -explode-pattern-binding-decls=true -disable-objc-attr-requires-foundation-module -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference | %FileCheck %s
+// RUN: not %target-swift-frontend -typecheck -dump-ast -disable-objc-attr-requires-foundation-module %s -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference > %t.ast
 // RUN: %FileCheck -check-prefix CHECK-DUMP %s < %t.ast
 // REQUIRES: objc_interop
 
@@ -2381,11 +2381,3 @@ class SR12801 {
   @objc subscript<T>(foo : [T]) -> Int { return 0 }
   // expected-error@-1 {{subscript cannot be marked @objc because it has generic parameters}}
 }
-
-// async cannot be compiled with @objc.
-class Concurrency {
-  @objc func doBigJob() async -> Int { return 0 } // expected-error{{'async' function cannot be represented in Objective-C}}
-
-  @objc func takeAnAsync(_ fn: () async -> Int) { } // expected-error{{method cannot be marked @objc because the type of the parameter cannot be represented in Objective-C}}
-  // expected-note@-1{{'async' function types cannot be represented in Objective-C}}
-}

test/attr/attr_objc_async.swift

@@ -0,0 +1,14 @@
+// RUN: %target-swift-frontend -disable-objc-attr-requires-foundation-module -typecheck -verify -verify-ignore-unknown %s -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference -enable-experimental-concurrency
+// RUN: %target-swift-ide-test -skip-deinit=false -print-ast-typechecked -source-filename %s -function-definitions=true -prefer-type-repr=false -print-implicit-attrs=true -explode-pattern-binding-decls=true -disable-objc-attr-requires-foundation-module -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference -enable-experimental-concurrency | %FileCheck %s
+// RUN: not %target-swift-frontend -typecheck -dump-ast -disable-objc-attr-requires-foundation-module %s -swift-version 4 -enable-source-import -I %S/Inputs -enable-swift3-objc-inference -enable-experimental-concurrency > %t.ast
+// RUN: %FileCheck -check-prefix CHECK-DUMP %s < %t.ast
+// REQUIRES: objc_interop
+
+// async cannot be compiled with @objc.
+// CHECK-DUMP: class Concurrency
+class Concurrency {
+  @objc func doBigJob() async -> Int { return 0 } // expected-error{{'async' function cannot be represented in Objective-C}}
+
+  @objc func takeAnAsync(_ fn: () async -> Int) { } // expected-error{{method cannot be marked @objc because the type of the parameter cannot be represented in Objective-C}}
+  // expected-note@-1{{'async' function types cannot be represented in Objective-C}}
+}