Fix label def points
Fix label def points

Define labels at the same point as the instruction they are labeling.
This avoids situations where a label is defined before a page boundary
and its labeled instruction is defined after the page boundary.

kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom