1175: Fix bugs and add error log about macro expansion r=matklad a=edwin0cheng
This PR fixed / add following things:
* Add a fused count which stop recursion of macro expansion in name resolution.
* Add some logs when macro expansion fails
* Add `$crate` meta variable support in mbe, which create a `$crate` ident token in token tree.
* Fixed matching a `$REPEAT` pattern inside a subtree, e.g. `(fn $name:ident {$($i:ident)*} ) => {...}`
* Remove composite-able punct token in syntax node to token conversion.
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
fa15c4d75e