Things I'm planning to address soon. If anyway else wants to take any of these, just comment here.

• core/std library cleanup #1189 (fixed in core/std lib reorg, small fixes, high-level erc20 test #1196)
• remove evm-specifics from contract lowering (core/std lib reorg, small fixes, high-level erc20 test #1196)
• HIR printer doesn't show attributes (hir: pretty-print attributes, support attributes on use and trait-associated items #1198)
• mir: remove zero-sized effect args
• mir: unwrap "newtype"-style structs (eg struct Foo { inner: u256 } becomes u256) (mir: newtype peeling #1199)
• mir: remove evm intrinsic enum
• AbiSize trait should be generic (or be replaced by AbiEncode<A: Abi>::ENCODED_SIZE)
• remove hardcoded int-size-masking code from codegen