fix: consider protocol loss when calculating shares to revoke and use 512-bit mulDivs in CollateralTracker

[dyedm1]

No description provided.

[guil-lambert]

Ok, I had to check. The expression on the liquidation branch is different, but it turns out it's the exact same value:

From the liquidation branch:

            // must mint the correct amount of shares (∆) so that the redeemable value is exactly equal to A, the requested assets
            // tA: total assets in vault (ie. totalAssets())
            // tS: total supply of shares (ie. totalSupply)
            // ∆: desired number of shares to be minted
            // A: requested assets
            // B: transferred shares from liquidatee (ie. delegateeBalance)
            //
            // Redeemable value = assets === delegatorShares * totalAssets() / newTotalSupply
            //
            // A = (B + ∆) * tA / (tS + ∆)
            // ∆ * (tA - A) = A * tS - B * tA
            // ∆ = (A*tS - B*tA)/(tA-A)

            uint256 tA = totalAssets();
            unchecked {
                // mint shares to complete to requested amount
                _mint(
                    delegator,
                    Math.mulDiv(assets, totalSupply, tA - assets) -
                        Math.mulDiv(delegateeBalance, tA, tA - assets)
                );
            }

So the final expressions are:

Math.mulDiv(assets, totalSupply - delegateeBalance, totalAssets() - assets) -delegateeBalance)

versus

Math.mulDiv(assets, totalSupply, tA - assets) - Math.mulDiv(delegateeBalance, tA, tA - assets)

It's the exact same final expression once we expand yours.

[dyedm1]

Yep. I did it that way to save a mulDiv.