There was an obscure bug in parse_expr(), used to evaluate 'if df',
where it could skip past the end of the line marker.
If this happened inside an expanded macro, then after that was the
next line...
In other cases it might be worse.
Now that this is fixed, another check for line end junk can be enabled.
which have an general (source) argument and an AC destination.
There are no FPP instrs which have 1 general source arg;
only with 1 general destination (even TSTF).
by using long double where available.
Unfortunately, it won't be available everywhere, so a better solution
would still be nice.
Also, sometimes rounding of smaller sizes doesn't work right yet.
