4. Call INTERPRET

In other words, BOOT interprets bytes directly following
CURRENT as Forth source code. This code will typically
initialize all subsystems and then call RDLN$. As soon as
this is called, INTERPRET will begin reading from RDLN< which
reads from KEY.

In the "/emul" binaries, "HERE" is readjusted to "CURRENT @" so
that we don't have to relocate compiled dicts. Note that in
this context, the initialization code is fighting for space
with HERE: New entries to the dict will overwrite that code!
Also, because we're barebone, we can't have comments. This can
lead to peculiar code in this area where we try to "waste"
space in initialization code.