Rollup merge of #80870 - petrochenkov:bmactable, r=oli-obk

resolve: Simplify built-in macro table

We don't use full `SyntaxExtension`s from the table, only `SyntaxExtensionKind`s, and `Ident` in `register_builtin_macro` always had dummy span. This PR removes unnecessary data from the table and related function signatures.

Noticed when reviewing #80850.

diff --cc compiler/rustc_resolve/src/lib.rs
Simple merge

diff --cc compiler/rustc_resolve/src/macros.rs
Simple merge