Add (failing) test for nested types

Author: hlopko

test/Interop/Cxx/templates/Inputs/SwiftClassTemplateNestedTypeModule.swift

@@ -0,0 +1,7 @@
+import ClassTemplateNestedTypeForSwiftModule
+
+public func receiveShipEngine(_ i: inout Ship<Bool>.Engine) {}
+
+public func returnShipEngine() -> Ship<Bool>.Engine {
+  return Ship<Bool>.Engine()
+}

test/Interop/Cxx/templates/Inputs/class-template-nested-type-for-swift-module.h

@@ -0,0 +1,11 @@
+#ifndef TEST_INTEROP_CXX_TEMPLATES_INPUTS_CLASS_TEMPLATE_NESTED_TYPE_FOR_SWIFT_MODULE_H
+#define TEST_INTEROP_CXX_TEMPLATES_INPUTS_CLASS_TEMPLATE_NESTED_TYPE_FOR_SWIFT_MODULE_H
+
+template <class T> struct Ship {
+    struct Engine {
+        T power;
+    };
+};
+
+
+#endif // TEST_INTEROP_CXX_TEMPLATES_INPUTS_CLASS_TEMPLATE_NESTED_TYPE_FOR_SWIFT_MODULE_H

test/Interop/Cxx/templates/Inputs/module.modulemap

@@ -103,6 +103,11 @@ module ClassTemplateInNamespaceForSwiftModule {
   requires cplusplus
 }
 
+module ClassTemplateNestedTypeForSwiftModule {
+  header "class-template-nested-type-for-swift-module.h"
+  requires cplusplus
+}
+
 module MemberTemplates {
   header "member-templates.h"
   requires cplusplus

test/Interop/Cxx/templates/swift-class-instantiation-nested-type-module-interface.swift

@@ -0,0 +1,9 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swiftxx-frontend -emit-module -o %t/SwiftClassTemplateNestedTypeModule.swiftmodule %S/Inputs/SwiftClassTemplateNestedTypeModule.swift -I %S/Inputs -enable-library-evolution -swift-version 5
+// RUN: %target-swift-ide-test -print-module -module-to-print=SwiftClassTemplateNestedTypeModule -I %t/ -source-filename=x -enable-cxx-interop | %FileCheck %s
+
+// REQUIRES: SR-13261
+
+// CHECK: import ClassTemplateNestedTypeForSwiftModule
+// CHECK: func receiveShipEngine(_ i: inout Space.__CxxTemplateInstN5Space4ShipIbEE)
+// CHECK: func returnShipEngine() -> Space.__CxxTemplateInstN5Space4ShipIbEE