Repair and speed up safe-copy-tree and make it internal (bug#61962)

There is no particular requirement for safe-copy-tree so let's make it
internal for now.  The new implementation is faster and more correct.

* doc/lispref/lists.texi (Building Lists):
* etc/NEWS:  Remove doc and announcement.
* lisp/subr.el (safe-copy-tree--seen, safe-copy-tree--1)
(safe-copy-tree): Remove old version.
* lisp/emacs-lisp/bytecomp.el (bytecomp--copy-tree-seen)
(bytecomp--copy-tree-1, bytecomp--copy-tree): Add new version.
(byte-compile-initial-macro-environment): Use it.
* test/lisp/subr-tests.el (subr--safe-copy-tree):
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp--copy-tree):
Move and improve tests.

1 files changed, 0 insertions, 13 deletions

diff --git a/doc/lispref/lists.texi b/doc/lispref/lists.texi
index 3478049c84f..a509325854f 100644
--- a/doc/lispref/lists.texi
+++ b/doc/lispref/lists.texi
@@ -708,19 +708,6 @@ non-@code{nil}, it copies vectors too (and operates recursively on
 their elements).  This function cannot cope with circular lists.
 @end defun
 
-@defun safe-copy-tree tree &optional vecp
-This function returns a copy of the tree @var{tree}.  If @var{tree} is
-a cons cell, this make a new cons cell with the same @sc{car} and
-@sc{cdr}, then recursively copies the @sc{car} and @sc{cdr} in the
-same way.
-
-Normally, when @var{tree} is anything other than a cons cell,
-@code{copy-tree} simply returns @var{tree}.  However, if @var{vecp} is
-non-@code{nil}, it copies vectors and records too (and operates
-recursively on their elements).  This function handles circular lists
-and vectors, and is thus slower than @code{copy-tree} for typical cases.
-@end defun
-
 @defun flatten-tree tree
 This function returns a ``flattened'' copy of @var{tree}, that is,
 a list containing all the non-@code{nil} terminal nodes, or leaves, of