cli: modern_hush: Add upstream commits up to 2nd October 2023.

cli: modern_hush: Add upstream commits up to 2nd October 2023.

This commit adds the following hush busybox upstream commits:
791b222dd55d ("sleep: fix "sleep -- ARGS"")
5353df91cba7 ("Update applet size estimates")
e41e481fd571 ("hush: fix a compile failure")
07a95cfcabb0 ("ash: disable check for "good" function name, bash does not check this")
e5692e2342c6 ("hush: quote values in "readonly" output")
96769486e20f ("shell: move varcmp() to shell_common.h and use it in hush")
bab8828b0dad ("hush: fix expansion of space in "a=${a:+$a }c" construct")
b5be8da350b5 ("hush: make "false" built-in")
6824298ab4d3 ("hush: fix ELIF cmd1;cmd2 THEN ... not executing cmd2, closes 15571")
3a7f00eadcf4 ("hush: add comment about abort on syntax error %{^}")
acae889dd972 ("ash,hush: tab completion of functions and aliases")
90b607d79a13 ("hush: quote variable values printed by "set" (match ash behavior)")
6748e6494c22 ("hush (NOMMU): fix LINENO in execed children")
fd5fb2d2b596 ("hush: speed up "big heredoc" code")
1409432d072e ("hush: add TODO comment")
93ae7464e6e4 ("hush: restore SIGHUP handling, this time explain why we do what we do")
1fdb33bd07e5 ("hush: restore tty pgrp on SIGHUP")
6101b6d3eaa0 ("hush: remove special handling of SIGHUP")
93e0898c663a ("shell: fix SIGWINCH and SIGCHLD (in hush) interrupting line input, closes 15256")
969e00816835 ("hush: code shrink")
27be0e8cfeb6 ("shell: fix compile failures in some configs")
7d1c7d833785 ("ash,hush: use HOME for tab completion and prompts")
21afddefd258 ("hush: fix "error: invalid preprocessing directive ##"")
e53c7dbafc78 ("hush: fix set -n to act immediately, not just after run_list()")
574b9c446da1 ("hush: fix var_LINENO3.tests failure")
49bcf9f40cff ("hush: speed up ${x//\*/|} too")
53b2fdcdba4c ("*: add NOINLINEs where code noticeably shrinks")
7c3e96d4b3d4 ("shell: use more compact SHELL_ASH / HUSH config defines. no code changes")
62f1eed1e191 ("hush: in a comment, document what -i might be doing")
aaf3d5ba74c5 ("shell: tweak --help")
db5546ca1018 ("libbb: code shrink: introduce and use [_]exit_SUCCESS()")
931c55f9e2b4 ("libbb: invert the meaning of SETUP_ENV_NO_CHDIR -> SETUP_ENV_CHDIR")
12566e7f9b5e ("ash,hush: fix handling of SIGINT while waiting for interactive input")
987be932ed3c ("*: slap on a few ALIGN_PTR where appropriate")

Signed-off-by: Francis Laniel <francis.laniel@amarulasolutions.com>