5982 - start putting block labels on the var stack

Before:
  we detected labels using a '$' at the start of an arg, and turned them
  into literals.

After:
  we put labels on the var stack and let the regular lookup of the var
  stack handle labels.

This adds complexity in one place and removes it from another. The crucial
benefit is that it allows us to store a block depth for each label. That
will come in handy later.

All this works only because of a salubrious coincidence: Mu labels are
always at the start of a block, and jumps always refer to the name at the
start of a block, even when the jump is in the forwards direction. So we
never see label uses before definitions.

Note on CI: this currently only works natively, not emulated.

0 files changed, 0 insertions, 0 deletions