Cleaning away make.last is counterproductive.

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Promise a few more things to the compiler

Don't think it makes a different though.

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Pass interpreter to avoid repeated lookup

Also avoid bounds check on vector in non-debug mode.

Signed-off-by: Stefan Marr <git@stefan-marr.de>