Rollup merge of #93915 - Urgau:rfc-3013, r=petrochenkov

Implement --check-cfg option (RFC 3013), take 2

This pull-request implement RFC 3013: Checking conditional compilation at compile time (https://github.com/rust-lang/rfcs/pull/3013) and is based on the previous attempt https://github.com/rust-lang/rust/pull/89346 by `@mwkmwkmwk` that was closed due to inactivity.

I have address all the review comments from the previous attempt and added some more tests.

cc https://github.com/rust-lang/rust/issues/82450
r? `@petrochenkov`

compiler/rustc_span/src/symbol.rs

@@ -911,6 +911,7 @@ symbols! {
         naked,
         naked_functions,
         name,
+        names,
         native_link_modifiers,
         native_link_modifiers_as_needed,
         native_link_modifiers_bundle,
@@ -1482,6 +1483,7 @@ symbols! {
         va_list,
         va_start,
         val,
+        values,
         var,
         variant_count,
         vec,