Pick e42520c for libffi

Author: fkistner

native/libffi/src/aarch64/ffi.c

@@ -660,12 +660,13 @@ ffi_call_int (ffi_cif *cif, void (*fn)(void), void *orig_rvalue,
 		state.ngrn = N_X_ARG_REG;
 		/* Note that the default abi extends each argument
 		   to a full 64-bit slot, while the iOS abi allocates
-		   only enough space. */
+		   only enough space, except for variadic arguments. */
 #ifdef __APPLE__
-		memcpy(d, a, s);
-#else
-		*(ffi_arg *)d = ext;
+		if (!state.allocating_variadic)
+		  memcpy(d, a, s);
+		else
 #endif
+		  *(ffi_arg *)d = ext;
 	      }
 	  }
 	  break;