This fixes a subtle bug in GenericGraph. Basically, if the label of an
Edge was the Empty data structure, whose `operator==` always returns
`true`, the comparison between edges was broken.
Various parts of revng replace `llvm::GlobalVariable`s representing CSVs
with Allocal/Load/Store. In particular, these are PromoteCSV,
RootAnalyzer and PromoteGlobalToLocalVars.
Before this commit, those places were sloppy when replacing CSVs with
Alloca/Load/Store, and did that iterating on a container sorted by
pointers. This caused Alloca/Load/Store to be emitted in different order
accross runs, which in turn caused more non-determinism down the
pipeline.
This commit fixes the non-deterministic behavior, sorting CSVs based on
their names, which should always be present and deterministic.
This commit moves stuff around to enforce complete information being
present by the time the "Internal" assembly output is ready.
Because of that, the "Internal" format needed to change, now it uses
tag representation close to PTML as opposed to the one close to LLVM's
used before now.
We used to support having a single `void` argument. It was for some
C-compatibility ambitions, but just omitting the argument is perfectly
fine.
Also, the DWARF importer has been fixed to handle typedef'd void as
arguments.
More in general, arguments are now required to always have a size.
Since pointer to copy system got straightenned up, the old way of
marking them (`abi::Definition::UsePointerToCopyForStackArguments`)
is no longer needed.
This lets us drop the repeated alignment calculations at
the "leaves" of the conversion. Since new distributor already
provides the necessary information, we can just grab it from
there.
Alessandro Di Federico