Add AT&T ksh93 package

[sebifeld]

Description / Steps to reproduce the issue

Add AT&T ksh93 package, please. That is David Korn's original Korn Shell.

Source repro is at https://github.com/ksh93/ksh

Expected behavior

ksh93 -c 'print -- $(( sin(4.0) ))' works

Actual behavior

ksh93 -c 'print -- $(( sin(4.0) ))' does not work, /usr/bin/ksh93 not found.

Verification

• I have verified that my MSYS2 is up-to-date before submitting the report (see https://www.msys2.org/docs/updating/)

Windows Version

MSYS2_NT-10.0-1904

Are you willing to submit a PR?

No response

[jeremyd2019]

which package requires this for its build process?

[jeremyd2019]

for some history, we had #5243, and I opened ksh93/ksh#834

[sebifeld]

which package requires this for its build process?

Many bioinformatics packages (blast, Staden, NIH's tookchain for assembly visualizing, editing, and finishing of NGS data, ...), processing of astronomy data and other things.
ksh93 is the only shell with C99-style floating point math, with also understands the difference of -0.0/+0.0, +Nan,+Nan and so on, which perl does very poorly. So ksh93 is very popular with non-informatics scientists.