Suspend temp .elc production when native compiling till when necessary

Suspend temp .elc production when native compiling till when necessary

* lisp/emacs-lisp/bytecomp.el (byte-to-native-output-buffer-file):
Rename from `byte-to-native-output-file'.
(byte-write-target-file): Update.
(byte-compile-file): Write the temporary .elc only when not native
compiling.
(byte-compile-file): Kill the .elc buffer only when not native
compiling.
* lisp/emacs-lisp/comp.el (batch-byte+native-compile): Instead of just
renaming the temporary .elc make use of `byte-write-target-file' to
write it down and kill the temporary buffer.