They currently fail because for vector values, gcc casts the view, not
the value, so vec4 cast to ivec4 simply views the bits as int rather
than doing the actual conversion.
* / % %% + -
As a bonus, includes partial tests for a few extra operators. Several
things are broken at this stage, but uncommitted code is already
working.
They even found a bug in the addressing mode functions :) (I'd forgotten
that I wanted signed offsets from the pointer and thus forgot to cast
st->b to short in order to get the sign extension)
