move ffi_prep_cif_core to ffi_common.h

include/ffi.h.in

@@ -229,15 +229,6 @@ typedef struct {
 #endif
 } ffi_cif;
 
-/* Used internally, but overridden by some architectures */
-ffi_status ffi_prep_cif_core(ffi_cif *cif,
-			     ffi_abi abi,
-			     unsigned int isvariadic,
-			     unsigned int nfixedargs,
-			     unsigned int ntotalargs,
-			     ffi_type *rtype,
-			     ffi_type **atypes);
-
 /* ---- Definitions for the raw API -------------------------------------- */
 
 #ifndef FFI_SIZEOF_ARG