Use load-read-function in byte-compile-from-buffer

* lisp/emacs-lisp/bytecomp.el (byte-compile-from-buffer): Use
load-read-function.

* src/lread.c (syms_of_lread): Adjust doc string (bug#33723).

etc/NEWS

@@ -872,6 +872,10 @@ Emacs buffers, like indentation and the like.  The new ert function
 
 * Incompatible Lisp Changes in Emacs 29.1
 
+---
+** 'byte-compile-from-buffer' now uses 'load-read-function'.
+It previously called 'read' directly.
+
 ** User option 'mail-source-ignore-errors' is now obsolete.
 The whole mechanism for prompting users to continue in case of
 mail-source errors has been removed, so this option is no longer
@@ -977,6 +981,7 @@ functions.
 
 * Lisp Changes in Emacs 29.1
 
++++
 ** New function 'readablep'.
 This function says whether an object can be written out and then
 read back by the Emacs Lisp reader.

lisp/emacs-lisp/bytecomp.el

@@ -2294,7 +2294,7 @@ With argument ARG, insert value in current buffer after the form."
 	  (setq byte-compile-read-position (point)
 		byte-compile-last-position byte-compile-read-position)
           (let* ((lread--unescaped-character-literals nil)
-                 (form (read inbuffer))
+                 (form (funcall load-read-function inbuffer))
                  (warning (byte-run--unescaped-character-literals-warning)))
             (when warning (byte-compile-warn "%s" warning))
 	    (byte-compile-toplevel-file-form form)))

src/lread.c

@@ -5272,7 +5272,9 @@ of the file, regardless of whether or not it has the `.elc' extension.  */);
   Vcurrent_load_list = Qnil;
 
   DEFVAR_LISP ("load-read-function", Vload_read_function,
-	       doc: /* Function used by `load' and `eval-region' for reading expressions.
+	       doc: /* Function used for reading expressions.
+It is used by `load', `eval-region' and `byte-compile-from-buffer'.
+
 Called with a single argument (the stream from which to read).
 The default is to use the function `read'.  */);
   DEFSYM (Qread, "read");