Add back unnecessarily redacted headers that now exist

I think this might have been an artifact of the old CFLite redactions?
Either way, these headers are now available in this repository. The real
CoreFoundation guards these includes with `#ifndef CF_OPEN_SOURCE` but
that doesn't seem relevant here. There are also other includes guarded
by that which are not (yet? 😆) available in this repository, so I did
not include them here.

Author: copumpkin

CoreFoundation/Base.subproj/CoreFoundation.h

@@ -77,6 +77,8 @@
 #include <CoreFoundation/CFSocket.h>
 #include <CoreFoundation/CFMachPort.h>
 
+#include <CoreFoundation/CFAttributedString.h>
+#include <CoreFoundation/CFNotificationCenter.h>
 
 #endif
 

CoreFoundation/Base.subproj/SwiftRuntime/CoreFoundation.h

@@ -92,6 +92,7 @@
 #include <CoreFoundation/CFSocket.h>
 #include <CoreFoundation/CFMachPort.h>
 #include <CoreFoundation/CFAttributedString.h>
+#include <CoreFoundation/CFNotificationCenter.h>
 
 #include <CoreFoundation/CFURLPriv.h>
 #include <CoreFoundation/CFURLComponents.h>