Implement a new function directory-files-recursively

* doc/lispref/files.texi (Contents of Directories): Document
directory-files-recursively.

* etc/NEWS: Mention directory-files-recursively.

* lisp/files.el (find-files): New function.
Sync with upstream vhdl mode v3.36.1

* lisp/progmodes/vhdl-mode.el (vhdl-version, vhdl-time-stamp): Update.
(vhdl-compiler-alist): Anchor all error regexps.
(vhdl-compile-use-local-error-regexp): Change default to nil.
(vhdl-asort, vhdl-anot-head-p): Remove.
(vhdl-aput, vhdl-adelete, vhdl-aget): Simplify.
Remove optional argument of vhdl-aget and update all callers.
(vhdl-import-project): Also set `vhdl-compiler'.
Sync with upstream verilog-mode revision aa4b777

* lisp/progmodes/verilog-mode.el (verilog-mode-version): Update.
(verilog-auto-end-comment-lines-re, verilog-end-block-ordered-re)
(verilog-set-auto-endcomments): Automatically comment property/
endproperty blocks to match other similar blocks like sequence/
endsequence, function/endfunction, etc.  Reported by Alex Reed.
(verilog-set-auto-endcomments): Fix end comments for functions of
type void, etc.  Detect the function- or task-name when
auto-commenting blocks that lack an explicit portlist.
Reported by Alex Reed.
(verilog-nameable-item-re): Fix nameable items that can have an
end-identifier to include endchecker, endgroup, endprogram,
endproperty, and endsequence.  Reported by Alex Reed.
(verilog-preprocessor-re, verilog-beg-of-statement):
Fix indentation of property/endproperty around pre-processor
directives.  Reported by Alex Reed.
(verilog-label-be): When auto-commenting a buffer, consider
auto-comments on all known keywords (not just a subset thereof).
Reported by Alex Reed.
(verilog-beg-of-statement): Fix labeling do-while blocks, bug842.
Reported by Alex Reed.
(verilog-beg-of-statement-1, verilog-at-constraint-p):
Fix hanging with many curly-bracket pairs, bug663.
(verilog-do-indent): Fix electric tab deleting form-feeds.
Note caused by indent-line-to deleting tabls pre 24.5.
(verilog-auto-output, verilog-auto-input, verilog-auto-inout)
(verilog-auto-inout-module, verilog-auto-inout-in): Doc fixes.
(verilog-read-always-signals, verilog-auto-sense-sigs)
(verilog-auto-reset): Fix AUTORESET with always_comb and always_latch,
bug844.  Reported by Greg Hilton.

Author: Alex Reed <acreed4@gmail.com> (tiny change)
* lisp/progmodes/verilog-mode.el (verilog-no-indent-begin-re):
Fix `verilog-indent-begin-after-if' nil not honoring 'forever',
'foreach', and 'do' keywords.
(verilog-endcomment-reason-re, verilog-beg-of-statement):
Fix labeling do-while blocks, bug842.
(verilog-backward-token): Fix indenting sensitivity lists with named
events, bug840.