We treat macro calls as expressions (there's appropriate Into impl),
which causes problem if there's expresison and non-expression macro in
the same node (like in the match arm).
We fix this problem by nesting macor patterns into another node (the
same way we nest path into PathExpr or PathPat). Ideally, we probably
should add a similar nesting for macro expressions, but that needs
some careful thinking about macros in blocks: `{ am_i_expression!() }`.
3062: Implement slice pattern AST > HIR lowering r=jplatte a=jplatte
WIP. The necessary changes for parsing are implemented, but actual inference is not yet. Just wanted to upload what I've got so far so it doesn't get duplicated :)
Will fix#3043
Co-authored-by: Jonas Platte <jplatte+git@posteo.de>
