Leverage the declared ABI for conditional compilation of ink! core crates for compile time and binary size improvements/optimizations #2519
Description
Overview
ink! projects can now declare their target ABI in their manifest file (i.e. Cargo.toml).
The specified ABI is then propagated into the build environment as a cfg flag ink_abi.
Motivation
Some definitions (and related dependencies) in ink! core crates are only relevant to specific ABIs.
As an example SolEncode and SolDecode implementations for Rust/ink! "primitive" types in ink_primitives and the related alloy_sol_types dependency are unnecessary when the ABI is "ink". The same may NOT be true though for SCALE trait implementations for ink! specific types because those may still be used in storage which is SCALE encoded.
However, this probably doesn't only apply to ink_primitives but to other ink! core crates as well (e.g. ink, ink_env, ink_e2e e.t.c)
Design
TBD