Expand description
This module contains code to equate the input/output types appearing
in the MIR with the expected input/output types from the function
signature. This requires a bit of processing, as the expected types
are supplied to us before normalization and may contain opaque
impl Trait instances. In contrast, the input/output types found in
the MIR (specifically, in the special local variables for the
RETURN_PLACE the MIR arguments) are always fully normalized (and
contain revealed impl Trait values).