Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Update to FICL 3.03 (the last release before FICL4 rewrite).

The relevant changes for FreeBSD (excerpt from the release note):

* Newly implemented CORE EXT words: CASE, OF, ENDOF, and ENDCASE. Also
added FALLTHROUGH, which works like ENDOF but jumps to the instruction
just after the next OF.
* Bugfix: John-Hopkins locals syntax now accepts | and -- in the comment
(between the first -- and the }.)
* Bugfix: Changed vmGetWord0() to make Purify happier. The resulting
code is no slower, no larger, and slightly more robust.

Upgrade to FICL version 3.02. Anything wrong is my fault, everything right is
due Jon Mini.

PR: 36308
Submitted by: Jon Mini <mini@haikugeek.com>
MFC after: 4 weeks

Bring in ficl 2.05.

This version has a step debugger, which now completely replaces the
old trace feature. Also, we moved all of the FreeBSD-specific MI
code to loader.c, reducing the diff between this and the official
FICL distribution.

Apply a number of fixes for the Alpha platform.

Bring in FICL 2.04. No bump of loader version is required by this
commit.

Bring in ficl version 2.03. No version bump for loader.

Add EXCEPTION word set.

Make TIB handling use buffer size to conform with ANS Forth.

Add ANS MEMORY-ALLOC word set.

See the PRs for extensive details.

PR: kern/9412 kern/9442 kern/9514
Submitted by: PRs from Daniel Sobral <dcs@newsguy.com>

Fix includes; we were still pulling in <stdlib.h> in some places.
Support building a standalone interpreter with 'make testmain', remove
win32 and egregious gets() in testmain.c

Make this work in the libstand environment; don't use stdio/stdlib headers.

Add the Ficl (Forth Inspired Command Language) interpreter. If all goes well,
this will allow us to manage bloat in the loader by using a bytecoded HLL
rather than lots of C code. It also offers an opportunity for vendors
or others with special applications to significantly customise the boot
process without having to commit to a divergent code branch.

This early commit is to allow others to experiment with the most effective
mechanisms for integrating FICL with the loader as it currently stands.

Ficl is distributed with the following license conditions:

"Ficl is freeware. Use it in any way that you like, with the understanding
that the code is not supported."

All source files contain authorship attributions.

Obtained from: John Sadler (john_sadler@alum.mit.edu)