[m-dev.] proposal: rename the --generate-module-order option

[Zoltan Somogyi]

This option does not do anything on its own; it is only ever
consulted when making dependencies. I propose that we

- rename it to --generate-dependencies-record-trans-opt-order,
  or preferably something shorter that still gets its purpose across,
  and

- make it an only_opmode option.

At the moment the opmode for generating dependencies,
opma_generate_dependencies, has one argument which says
whether we should be building the .intN files as well.
The renamed option would effectively be specifying a second
argument which says whether we should output the computed
trans_opt dependency order to a file as well.

That's one proposal. The other is that regardless of whether
we do the above or not, the name of the file we output to
should be main_module.trans_opt_order, not simply main_module.order,
since the former is much more expressive.

Opinions?

The reason I am looking at this is that I am trying to finish
the trans_opt part of the "compilation in detail" chapter,
and I am not sure how the order works. It was originally
purely lexicographic order, but I know Peter has made
significant changes. I know these changes include deleting
edges from the dependency graph from which we can compute
a better, non-lexicographic order, and I know that the option
for deleting edges is private, but I don't know (a) why is it
private,(b) whether the whole computing-the-order-
nonlexicographically-from-dependencies system is private
as well, and (c) where the order is recorded (outside of the
.order file, which, since its creation is optional, I presume
the implementation itself does not use.)

Peter, can you please enlighten me?

Zoltan.