fn aggregate_field_layout(
base_ty: &Ty,
field: &str,
structs: &[MirStructDecl],
enums: &[MirEnumDecl],
) -> Result<FieldLayout, LowerError>fn aggregate_field_layout(
base_ty: &Ty,
field: &str,
structs: &[MirStructDecl],
enums: &[MirEnumDecl],
) -> Result<FieldLayout, LowerError>