Run "TZ=UTC0 admin/update-copyright".

This simplifies code, and helps performance in some cases (Bug#36597).
* src/lisp.h (hash_rehash_needed_p): Remove.  All uses removed.
(hash_rehash_if_needed): Remove.  All uses removed.
(struct Lisp_Hash_Table): Remove comment about rehashing hash tables.
* src/pdumper.c (thaw_hash_tables): New function.
(hash_table_thaw): New function.
(hash_table_freeze): New function.
(dump_hash_table): Simplify.
(dump_hash_table_list): New function.
(hash_table_contents): New function.
(Fdump_emacs_portable): Handle hash tables by eager rehashing.
(pdumper_load): Restore hash tables.
(init_pdumper_once): New function.

Run "TZ=UTC0 admin/update-copyright $(git ls-files)".

This mostly changes http: to https: in URLs.  It also updates
some URLs that have moved, removes some URLs that no longer
work, recommends against using procmail (procmail.org no
longer works), and removes some mentions of the
no-longer-existing Gmane, LPF and VTW.
It doesn't update all URLs, just the ones I had time for.
* GNUmakefile (help):
* admin/admin.el (manual-doctype-string):
* admin/charsets/Makefile.in (${charsetdir}/ALTERNATIVNYJ.map):
* admin/charsets/mapconv:
* lisp/net/soap-client.el (soap-create-envelope):
* lisp/org/org.el (org-doi-server-url):
* lisp/textmodes/bibtex.el (bibtex-generate-url-list):
Prefer https: to http: un URLs.

* src/alloc.c (memory_full): Just report "memory exhausted" if
failure occurs during initialization, since fancier recovery
schemes are not likely to work when not initialized.
* src/emacs.c (dump_error_to_string): Accept int, not enum
pdumper_load_result, since the result might not fit in the
enum.  Use strerror if it was derived from errno.  This is for
better diagnostics of pdump load failures.
(load_pdump_find_executable): Return char *, not enum.  2nd
arg is now pointer to buffer size, rather than pointer to
pointer to buffer.  All callers changed.  Use Emacs allocator
since they should now be OK even during early startup.
Use check_executable instead access, to use effective rather
than real permissions.
(load_pdump): Return void since callers ignore result.
Use int where enum could be too narrow.  Use heap rather
than stack for possibly-long string.  Prefer ptrdiff_t to
size_t.
* src/fileio.c (check_executable): Now extern.
* src/pdumper.c (pdumper_load): Return int that may have
errno added to it, for better diagnostics when loads fail.

* src/alloc.c (mark_maybe_pointer):
* src/pdumper.h (pdumper_object_p_precise):
Use pdumper_valid_object_type_p.
* src/pdumper.c (pdumper_find_object_type_impl):
* src/pdumper.h (pdumper_find_object_type):
Return int, not enum Lisp_Type.  All callers changed.
* src/pdumper.h (PDUMPER_NO_OBJECT): Do not cast -1 to enum
Lisp_Type; in theory, C18 says this could yield 7, which would
mean PDUMPER_NO_OBJECT == Lisp_Float (!).
(pdumper_valid_object_type_p): New function.

Say that pdumping cannot redump unless -batch is used.  Say that
the traditional unexec dumping method is by default not available,
and is deprecated.  Don't call dump files "portable", as dump files
are not any more portable than the Emacs executables themselves.
Just call them "dump files".  Similar, prefer "portable dumper"
(since the dumper code is portable) to "portable dumping" (since
the dump file is not).  Be more systematic about calling them
"dump files" instead of "dumped images" or whatnot.

* src/pdumper.c, src/pdumper.h: Reindent.

* src/charset.c (charset_table_size):
* src/pdumper.c (dump_private):
* src/sysdep.c (init_sigsegv):
* src/window.c (old_selected_window):
Now static.
* src/charset.c (charset_table_size):
Now int, since the value always fits in int.
* src/gtkutil.c (xg_gtk_initialized): Now present only if
HAVE_XWIDGETS, to make it clearer that this is an xwidgets
hack.  All uses changed.
* src/lread.c (ndefsubr): Remove; unused.
* src/pdumper.h: Use usual GNU indenting style for functions,
since my static-vs-extern checking hack relies on it.
(dump_public): Always declare; simpler and doesn’t hurt.
(pdumper_handle_page_fault): Remove unused decl.

* src/pdumper.c (pdumper_record_wd): New function.
(pdumper_load): Use xstrdup instead of strdup, as on
MS-Windows the latter uses the wrong heap.  Don't free a
NULL pointer.
* src/emacs.c (load_pdump): Support the use case where the
Emacs binary was renamed: look in exec-directory for the
pdump file whose base name is derived from the Emacs binary,
in addition to just emacs.pdmp.
(main): Call pdumper_record_wd to prepend CWD to the pdump
file name.
* src/fileio.c (file_name_absolute_p): Now extern.
* src/lisp.h (file_name_absolute_p): Add prototype.
* src/pdumper.h (pdumper_record_wd): Add prototype.

* doc/emacs/cmdargs.texi (Initial Options): Update the
documentation of where Emacs looks for the dump file.