97032a6dfa
Split rustc_mir The `rustc_mir` crate is the second largest in the compiler. This PR splits it up into 5 crates: - rustc_borrowck; - rustc_const_eval; - rustc_mir_dataflow; - rustc_mir_transform; - rustc_monomorphize.
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.