Support bitwise operations for bytesX types

[pcaversaccio]

Summary

Add support for the bitwise unary operator ~, the bitwise binary operators &, |, and ^, and the shift operators >> and <<. An example use case can be packing:

@internal
def _pack_1_1(left: bytes1, right: bytes1) -> bytes2:
    left = left & convert((max_value(uint256) << 248), bytes1)
    right = right & convert((max_value(uint256) << 248), bytes1)
    return left | (right >> 8)

[charles-cooper]

i think &, | and ^ are fine. shift operators and inverter operator ~ might be restricted to bytes32. (i guess they also have sane implementations for other bytesM types, but need extra instructions to ensure the rotation/bit cleaning happens correctly).

[pcaversaccio]

i think &, | and ^ are fine. shift operators and inverter operator ~ might be restricted to bytes32. (i guess they also have sane implementations for other bytesM types, but need extra instructions to ensure the rotation/bit cleaning happens correctly).

I'm fine with keeping the shift operators and the unary operator ~ to bytes32. The unary operator ~ for non-bytes32 types could be useful for some special use cases around math functions, where you want to get the max value of a type for example, i.e. ~empty(uint64) but since we also have max_value, the ergonomics is not improved by adding ~ to non-bytes32 types for this use case.