Adding info to gfunc record type

[MrDaiki]

Issue

Some iterative algorithms on program produce an output state that is lost for the moment (for example in liveness analysis, function live_fd throw the output variable set at the end of the analysis). This information could be useful for some algorithm (for example sign analysis).

Proposition

Change the gfunc record type to include a 'info field :

type 'len,'info,'asm gfunc = {
  ...
  f_info : 'info;
}

Consequences

Little modifications are needed but only in the caml part of the compiler.

[vbgl]

Sounds useful and simple to implement. Do you want to give it a try?

[vbgl]

Implemented in #1021.