Fix ptrauth C++ module include issue between extern (swiftlang#5212)

Fix “error: import of C++ module 'ptrauth' appears within extern "C" language linkage specification”

LLVM upstream makes  ptrauth  a module on this commit swiftlang/llvm-project@0481f04.

Swift 6.1 release introduced such change into the toolchain.

Author: Kyle-Ye

Sources/CoreFoundation/include/CFBase.h

@@ -669,6 +669,8 @@ CF_IMPLICIT_BRIDGING_DISABLED
 CF_EXPORT
 CFTypeRef CFMakeCollectable(CFTypeRef cf) CF_AUTOMATED_REFCOUNT_UNAVAILABLE;
 
+CF_EXTERN_C_END
+
 #if DEPLOYMENT_RUNTIME_SWIFT
 
 #if TARGET_RT_64_BIT
@@ -696,7 +698,5 @@ CFTypeRef CFMakeCollectable(CFTypeRef cf) CF_AUTOMATED_REFCOUNT_UNAVAILABLE;
 #define __ptrauth_cf_objc_isa_pointer
 #endif
 
-CF_EXTERN_C_END
-
 #endif /* ! __COREFOUNDATION_CFBASE__ */