✨ ERC20P related to issue #735

[wh173-c47]

Description

Created "ERC20P" related to issue #735, I don't know if it's still meaningful, but thought it would be convenient in some cases.
Changes are:

• Isolated ERC20 storage related constants.
• Isolated EIP2612 such that it can be implemented or not.
• Added ERC20P, very similar to actual ERC20 (but still added it in order to avoid messing up with current audited code), additions here are:
  • Upper bit packing of balances slots (arbitrarily u128 size, seems decent even for memecoins and their huge supplies), note I wondered about packing allowances too, there could be few needs, but due to allowance flow this would anyway add significant overhead gas).
  • An internal function to be able to set extra-data.
  • An internal function to be able to get extra-data.

Test has also been added (updated version of current ERC20).

Checklist

Ensure you completed all of the steps below before submitting your pull request:

• Ran forge fmt?
• Ran forge snapshot?
• Ran forge test?

Pull requests with an incomplete checklist will be thrown out.

[Vectorized]

Thanks for the great efforts. But may or may not merge. It’s my OCD to have it all in one file as much as possible, with zero cost abstraction.

[wh173-c47]

No problem, I get it, I have mine too.

Anyway it was pleasant to work on it and I might find some uses for it.

Thanks for you time and feedback.

[Vectorized]

@wh173-c47 tysm!!!

[wh173-c47]

Have to say this before I leave, but I have much respect and admiration for solady repo and your work, really. Thank you for that, for those snippet, for this inexhaustible source of knowledge.

I'm pretty busy, but someday I end up with free time so I feel the need to tell you, but I would really be honored to help, to contribute.

So feel free to reach me if any help is needed / specific taks are needed in priority, will always do my best and answer whenever I can.

Again thank you.