Changes 1559 to have a single shared pool for all transactions.

[MicahZoltu]

Rather than having two pools and a migration, we instead have a single transaction pool and legacy transactions are "upgraded" into 1559 transactions using a very naive strategy of just setting fee_cap == gas_bribe == gas_price.

While in here, I also made a few other minor changes since this is a consensus change and will require all clients update:

1. Renamed premium to bribe. I think this makes it more clear what this is, it is a bribe for the miner to convince them to include your transaction.
2. Changed the gas target calculation to be a bit simpler (per prior conversation with @i-norden)
3. Added special handling for when the gas_used == gas_target (no change in target for next block).
4. Adds missing assertion that gas_used wasn't more than 2x the gas target.
5. Added clarity to some names like fee_cap to fee_cap_per_gas and miner_bribe to miner_bribe_per_gas.

[eip-automerger]

Hi! I'm a bot, and I wanted to automerge your PR, but couldn't because of the following issue(s):

• EIP 1559 requires approval from one of (@i-norden, @mslipper, @AFDudley, @vbuterin, @econoar)

[i-norden]

I think instead of fee_cap == gas_bribe == gas_price

It is more accurate to say fee_cap == gas_price; gas_bribe = fee_cap - base_fee

In practice we should set gas_bribe = gas_price in the tx struct, but the amount of gas_price actually available for the bribe after burning the base_fee will be gas_price - base_fee i.e. fee_cap - base_fee.

Thanks for opening this! I haven't had a chance to look into the rest of this PR in more depth, will do so soon.

[MicahZoltu]

@i-norden I think what you are getting at is that miner_bribe_per_gas is a bit of a misnomer and really it is maximum_miner_bribe_per_gas. If so, I agree with you and have updated the EIP to reflect that.

Now that we have merged the other PR, I have rebased this and it is ready to merge once the authors approve it. Per discussion in Discord, we should make note that 711474afe36a9d778f7e1858b2c9a88b0bf146d0 is the commit hash for EIP-1559 that is currently on the integration testnet, and whatever the merge commit hash for this is will be the "target" EIP we are working toward and probably what new clients should implement.

@i-norden, @mslipper, @AFDudley, @vbuterin, @econoar

[MicahZoltu]

I have removed the prose text that referred to the transition as well (missed it in original PR).

[AbdelStark]

Looks good to me.