Port #[no_mangle] to new attribute parsing infrastructure

Signed-off-by: Jonathan Brouwer <jonathantbrouwer@gmail.com>

compiler/rustc_attr_parsing/src/context.rs

@@ -15,7 +15,7 @@ use rustc_session::Session;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 
 use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
-use crate::attributes::codegen_attrs::{ColdParser, OptimizeParser};
+use crate::attributes::codegen_attrs::{ColdParser, NoMangleParser, OptimizeParser};
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::deprecation::DeprecationParser;
 use crate::attributes::inline::{InlineParser, RustcForceInlineParser};
@@ -114,6 +114,7 @@ attribute_parsers!(
         Single<InlineParser>,
         Single<MayDangleParser>,
         Single<MustUseParser>,
+        Single<NoMangleParser>,
         Single<OptimizeParser>,
         Single<PubTransparentParser>,
         Single<RustcForceInlineParser>,