Add @_objcImpl test case with multiple modules

Author: beccadax

test/Interpreter/Inputs/objc_implementation.h

@@ -2,6 +2,7 @@
 
 @interface ImplClass : NSObject
 
++ (void)runTests;
 - (nonnull NSString *)someMethod;
 
 @end

test/Interpreter/Inputs/objc_implementation.modulemap

@@ -0,0 +1,3 @@
+framework module objc_implementation {
+  header "objc_implementation.h"
+}

test/Interpreter/objc_implementation.swift

@@ -1,20 +1,25 @@
-// RUN: %target-run-simple-swift(-import-objc-header %S/Inputs/objc_implementation.h) %s | %FileCheck %s
+// RUN: %target-run-simple-swift(-import-objc-header %S/Inputs/objc_implementation.h -D TOP_LEVEL_CODE -swift-version 5) %s | %FileCheck %s
 // REQUIRES: executable_test
 // REQUIRES: objc_interop
 
 import Foundation
 
 @_objcImplementation extension ImplClass {
+  @objc class func runTests() {
+    print(ImplClass().someMethod())
+    print(SwiftSubclass().someMethod())
+  }
+
   @objc func someMethod() -> String { "ImplClass.someMethod()" }
 }
 
-print(ImplClass().someMethod())
-// CHECK: ImplClass.someMethod()
-
 class SwiftSubclass: ImplClass {
   override func someMethod() -> String { "SwiftSubclass.someMethod()" }
 }
 
-print(SwiftSubclass().someMethod())
+// `#if swift` to ignore the inactive branch's contents
+#if swift(>=5.0) && TOP_LEVEL_CODE
+ImplClass.runTests()
+// CHECK: ImplClass.someMethod()
 // CHECK: SwiftSubclass.someMethod()
-
+#endif

test/Interpreter/objc_implementation_swift_client.swift

@@ -0,0 +1,48 @@
+//
+// Build objc_implementation.framework
+//
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/frameworks)
+// RUN: %empty-directory(%t/frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule)
+// RUN: %empty-directory(%t/frameworks/objc_implementation.framework/Headers)
+// RUN: cp %S/Inputs/objc_implementation.modulemap %t/frameworks/objc_implementation.framework/Modules/module.modulemap
+// RUN: cp %S/Inputs/objc_implementation.h %t/frameworks/objc_implementation.framework/Headers
+// RUN: %target-build-swift-dylib(%t/frameworks/objc_implementation.framework/objc_implementation) -emit-module-path %t/frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule/%module-target-triple.swiftmodule -module-name objc_implementation -F %t/frameworks -import-underlying-module -Xlinker -install_name -Xlinker %t/frameworks/objc_implementation.framework/objc_implementation %S/objc_implementation.swift
+
+//
+// Execute this file
+//
+// RUN: %empty-directory(%t/swiftmod)
+// RUN: %target-build-swift %s -module-cache-path %t/swiftmod/mcp -F %t/frameworks -o %t/swiftmod/a.out -module-name main
+// RUN: %target-codesign %t/swiftmod/a.out
+// RUN: %target-run %t/swiftmod/a.out | %FileCheck %s
+
+//
+// Execute again, without the swiftmodule this time
+//
+// RUN: mv %t/frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule %t/frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule.disabled
+// RUN: %empty-directory(%t/clangmod)
+// RUN: %target-build-swift %s -module-cache-path %t/clangmod/mcp -F %t/frameworks -o %t/clangmod/a.out -module-name main
+// RUN: %target-codesign %t/clangmod/a.out
+// RUN: %target-run %t/clangmod/a.out | %FileCheck %s
+
+// REQUIRES: executable_test
+// REQUIRES: objc_interop
+
+import Foundation
+import objc_implementation
+
+ImplClass.runTests()
+// CHECK: ImplClass.someMethod()
+// CHECK: SwiftSubclass.someMethod()
+
+print(ImplClass().someMethod())
+// CHECK: ImplClass.someMethod()
+
+class SwiftClientSubclass: ImplClass {
+  override func someMethod() -> String { "SwiftClientSubclass.someMethod()" }
+}
+
+print(SwiftClientSubclass().someMethod())
+// CHECK: SwiftClientSubclass.someMethod()
+