All "stop pings" are now explicitly made at appropriate places. This
fixes a problem I've introduced in the last commit where RAM+ was
unexpectedly part of a stable ABI because of "HERE" usage in dummy.fs.
This system will, anyways, soon change because boot.bin and z80c.bin
will be built during the same process (but there's a bit of retooling
to do before I get there).
Make LATEST configurable through a value in the binary instead of through
a ZASM constant. This enables the simple concatenation of compiled dicts and
simplifies the build process.
The commit ended up being much bigger than anticipated. This was a long thread
of underlying complexities. This lead to the creation of interesting concepts
such as (sysv).
My approach with RS was slightly wrong: RS' TOP was always containing current
IP. It worked, but it was problematic when came the time to introduce
RS-modifying words: it's impossible to modify RS in a word without immediately
messing your flow.
Therefore, what used to be RS' TOS has to be a variable that isn't changed
midway by RS-modifying words. I guess that's why RS is called *return* stack...
Big one.
This allows us to write higher order words directly in Forth, which is much
more convenient than writing post-immediate (see "NOT" structure in diff if
you want to see what I mean) structures in ASM.
These structures can then be written to ROM (rather than loaded in RAM for
definitions loaded at run-time).
That's quite a bit of tooling that was added, 2 compilations stages, but I
think it's well worth it.
