pub(crate) fn mir_for_ctfe_of_const_arg(
(did, param_did): (LocalDefId, DefId)
) -> &Body<'_>
mir_for_ctfe, but used to get the MIR of a const generic parameter.
The docs on
WithOptConstParam explain this a bit more, but the TLDR is that
we’d get cycle errors with
mir_for_ctfe, because typeck would need to typeck
the const parameter while type checking the main body, which in turn would try
to type check the main body again.