Recent Commits to freecom:master

CI: Use the previously built command.com for DOS builds

This allows us to get a little testing for free.

CI: Add Openwatcom 1.9 build on DOS

CI: Add download of DOS tools

CI: Move build tool install from workflow to script

Fix regression of 8ee281fd7

The LIBC makefile variable may be empty with some compilers, this
interacts with the `echoto` batch file causing an erroneous string
of 'ECHO is off' to appear in the response file.