✨ New CWIA

[Vectorized]

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Background

OZ is making their own implementation of CWIA which uses the extcodecopy pattern.

To bypass the 4337 storage restrictions.

Also, cuz of that 2771 meta-transactions thingy.

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Clone with immutable args

This will be simply an ERC1167 / z0age minimal proxy with the immutable arguments appended to the end of the bytecode.

As of the time of writing, both ERC1167 and z0age minimal proxies don't have Etherscan auto-verification support.

We'll use 1167, cuz OZ will probably ask Etherscan to add auto-verification support, and we wanna ride on their coattails. ;)

In the new simplified CWIA, there will not be a emit ReceiveETH(uint256) event on receive (which is from the CWIA variant that 0xSplits is using).

Then Clone.sol will be removed, and replaced with a few simple functions in LibClone.

The immutable args reading functions will use extcodecopy to read the immutable arguments.

Rationale

100 gas for the extcodecopy + 100 gas for the extcodesize isn't that big a dealbreaker, especially when gwei is already sub 10.

The extcodecopy pattern will also be much safer.

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ERC1967 with immutable args

This will also use the same extcodecopy pattern.

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Immutable args reading functions

/// @dev Returns the immutable arguments on `target`.
/// The `target` MUST be deployed via the clone with immutable args functions in this library.
/// Otherwise, the behavior is undefined.
function argsOnClone(address target) internal pure returns (bytes memory args);

/// @dev Returns the immutable arguments on `target`.
/// The `target` MUST be deployed via the ERC1967 functions in this library.
/// Otherwise, the behavior is undefined.
function argsOnERC1967(address target) internal pure returns (bytes memory args);

This is all we'll need. As extcodecopy burns 100 gas, it doesn't make sense to have the getArgUint256 functions. We'll just force users to retrieve all the arguments in a single call.

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Etherscan auto-verification support

At the time of writing:

• Solady ERC1967 minimal proxy with immutable args [YES]
• ERC1167 clone with immutable args [NO]

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Problems

The main problem is that there are already downstream dependents that use Solady's CWIA.

We will need to alert everyone who use Solady's CWIA.

We will have a legacy folder that places the old LibCWIA.sol (i.e. LibClone.sol with only the CWIA functions) and CWIA.sol (i.e. Clone.sol).

src/utils/LibClone.sol (only CWIA functions) -> src/utils/legacy/LibCWIA.sol
src/utils/Clone.sol -> src/utils/legacy/CWIA.sol

@clabby @wminshew @zobront