Make sure a switch statement does not have repetitive case statements.

Error found through LLVM post-2.1 svn.

Modules/_ctypes/libffi/src/x86/ffi_darwin.c

@@ -146,7 +146,9 @@ ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
     case FFI_TYPE_SINT64:
     case FFI_TYPE_FLOAT:
     case FFI_TYPE_DOUBLE:
+#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
     case FFI_TYPE_LONGDOUBLE:
+#endif
       cif->flags = (unsigned) cif->rtype->type;
       break;