* Do not produce .elc temporary file when unnecessary (bug#48978)

* lisp/emacs-lisp/bytecomp.el (byte-compile-file): Produce .elc
temporary files only when non native compiling or when native
compiling but `byte+native-compile' is non nil.

lisp/emacs-lisp/bytecomp.el

@@ -2067,16 +2067,17 @@ See also `emacs-lisp-byte-compile-and-load'."
 	  (insert "\n")			; aaah, unix.
 	  (cond
 	   ((null target-file) nil)     ;We only wanted the warnings!
-	   ((or byte-native-compiling
-		(and (file-writable-p target-file)
-		     ;; We attempt to create a temporary file in the
-		     ;; target directory, so the target directory must be
-		     ;; writable.
-		     (file-writable-p
-		      (file-name-directory
-		       ;; Need to expand in case TARGET-FILE doesn't
-		       ;; include a directory (Bug#45287).
-		       (expand-file-name target-file)))))
+	   ((and (or (null byte-native-compiling)
+                     (and byte-native-compiling byte+native-compile))
+                 (file-writable-p target-file)
+		 ;; We attempt to create a temporary file in the
+		 ;; target directory, so the target directory must be
+		 ;; writable.
+		 (file-writable-p
+		  (file-name-directory
+		   ;; Need to expand in case TARGET-FILE doesn't
+		   ;; include a directory (Bug#45287).
+		   (expand-file-name target-file))))
 	    ;; We must disable any code conversion here.
 	    (let* ((coding-system-for-write 'no-conversion)
 		   ;; Write to a tempfile so that if another Emacs
@@ -2105,11 +2106,9 @@ See also `emacs-lisp-byte-compile-and-load'."
 	      ;; recompiled).  Previously this was accomplished by
 	      ;; deleting target-file before writing it.
 	      (if byte-native-compiling
-                  (if byte+native-compile
-                      ;; Defer elc final renaming.
-                      (setf byte-to-native-output-file
-                            (cons tempfile target-file))
-                    (delete-file tempfile))
+                  ;; Defer elc final renaming.
+                  (setf byte-to-native-output-file
+                        (cons tempfile target-file))
                 (rename-file tempfile target-file t)))
 	    (or noninteractive
 		byte-native-compiling