Rollup merge of #133746 - oli-obk:push-xwyrylxmrtvq, r=jieyouxu

Change `AttrArgs::Eq` to a struct variant

Cleanups for simplifying https://github.com/rust-lang/rust/pull/131808

Basically changes `AttrArgs::Eq` to a struct variant and then avoids several matches on `AttrArgsEq` in favor of methods on it. This will make future refactorings simpler, as they can either keep methods or switch to field accesses without having to restructure code

compiler/rustc_parse/src/parser/mod.rs

@@ -1376,7 +1376,7 @@ impl<'a> Parser<'a> {
             AttrArgs::Delimited(args)
         } else if self.eat(&token::Eq) {
             let eq_span = self.prev_token.span;
-            AttrArgs::Eq(eq_span, AttrArgsEq::Ast(self.parse_expr_force_collect()?))
+            AttrArgs::Eq { eq_span, value: AttrArgsEq::Ast(self.parse_expr_force_collect()?) }
         } else {
             AttrArgs::Empty
         })