Enabled manual gas handling.

[orizi]

This change is 

[gilbens-starkware]

Reviewed 3 of 4 files at r1, all commit messages.
Reviewable status: 3 of 4 files reviewed, 1 unresolved discussion (waiting on @orizi)

---

crates/cairo-lang-lowering/src/db.rs line 484 at r1 (raw file):

                    }
                }
                stack.extend(info.arms().iter().map(|arm| arm.block_id));

I think this may be more readable.

Suggestion:

                let arms = info.arms().iter();
                if let MatchInfo::Extern(s) = info {
                    direct_callees.push(s.function);
                    if DependencyType::Cost == dependency_type
                        && withdraw_gas_fns.contains(&s.function)
                    {
                        // Not following the option when successfully fetched gas.
                        arms.next();
                    }
                }
                stack.extend(arms.map(|arm| arm.block_id));

[gilbens-starkware]

Reviewed 1 of 1 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @orizi)