Rollup merge of #114704 - bvanjoi:fix-114636, r=compiler-errors

parser: not insert dummy field in struct

Fixes #114636

This PR eliminates the dummy field, initially introduced in #113999, thereby enabling unrestricted use of `ident.unwrap()`. A side effect of this action is that we can only report the error of the first macro invocation field within the struct node.

An alternative solution might be giving a virtual name to the macro, but it appears more complex.(rust-lang/rust#114636 (comment)). Furthermore, if you think rust-lang/rust#114636 (comment) is a better solution, feel free to close this PR.

Author: matthiaskrgr