This should make tests a bit more convenient to write and debug.
Moreover, begin de de-IX-ization of parseExpr. I have, in a local WIP, a
parseExpr implemented using a recursive descent algo, it passes all tests, but
it unfortunately assembles a faulty zasm. I have to find the expressions that
it doesn't parse properly.
But before I do that, I prefer to commit these significant improvements I've
been making to tests harness in parallel of this development.
a034f63e23