After having over 600 failing tests at one point, this does feel good.
Even better, most of the risc/interpreter tests where i didn't change anything came gree without changing the tests. ie we have binary compatibility.
Also pass the source into the compile method.
This way compiler can be reused for subsequent compile.
Does remove some double boots, but no major time save
next's position was only updated initially
previous logic relied on pushing everything long rightly
but it wasn't right, and no harm in setting position twice,
as events only fire if there is real change
