Revert "PrintAsObjC Test: Extract what needs Objective-C out of cdecl-official"

This reverts commit a55b190.

Author: hamishknight

test/PrintAsObjC/cdecl-official-for-objc-clients.swift

@@ -4,12 +4,14 @@
 /// Generate cdecl.h
 // RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) \
 // RUN:   %t/Lib.swift -emit-module -verify -o %t -emit-module-doc \
-// RUN:   -emit-clang-header-path %t/cdecl.h \
+// RUN:   -emit-objc-header-path %t/cdecl.h \
 // RUN:   -enable-experimental-feature CDecl
 
 /// Check cdecl.h directly
 // RUN: %FileCheck %s --input-file %t/cdecl.h
+// RUN: %check-in-clang %t/cdecl.h
 // RUN: %check-in-clang-c %t/cdecl.h -Wnullable-to-nonnull-conversion
+// RUN: %check-in-clang-cxx %t/cdecl.h
 
 /// Build a client against cdecl.h
 // RUN: %clang -c %t/Client.c -fmodules -I %t \