globskipdots is not disabled by default In POSIX mode

[Emanuele Torre]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -g -O2
uname output: Linux t420 5.15.58-2-lts #1 SMP Mon, 01 Aug 2022
19:44:08 +0000 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 5.2
Patch Level: !PATCHLEVEL!
Release Status: rc2

Description:
        bash 5.2 has introduced the `globskipdots' shopt which prevents
        pathname expansion to match "." and ".." and is on by default.

        When bash is starts in POSIX mode, it is also on by default,
        it probably should not be for portability reasons.

Repeat-By:
        bash-5.1$ ./bash --posix -c 'echo "$BASH_VERSION" .*'
        5.2.0(4)-rc2 .build .gdb_history .git .gitignore .made

        bash-5.1$ (exec -a sh ./bash -c 'echo "$BASH_VERSION" .*')
        5.2.0(4)-rc2 .build .gdb_history .git .gitignore .made

Fix:
        bash should turn globskipdots off at least when it starts in
        POSIX mode.
        It could also turn it off when `set -o posix' is run or
        `POSIXLY_CORRECT' is set.