[gcc r17-2225] gccrs: Fix ICE when ident is a lang item

https://gcc.gnu.org/g:39356a0993305fb65d04c45c85749df694edefa5

commit r17-2225-g39356a0993305fb65d04c45c85749df694edefa5
Author: Philip Herron <[email protected]>
Date:   Sat Apr 18 22:23:41 2026 +0100

    gccrs: Fix ICE when ident is a lang item
    
    gcc/rust/ChangeLog:
    
            * ast/rust-ast-collector.cc (TokenCollector::visit): check for lang item
    
    Signed-off-by: Philip Herron <[email protected]>

Diff:
---
 gcc/rust/ast/rust-ast-collector.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gcc/rust/ast/rust-ast-collector.cc b/gcc/rust/ast/rust-ast-collector.cc
index 12f3e106c8f0..60be5e4475d5 100644
--- a/gcc/rust/ast/rust-ast-collector.cc
+++ b/gcc/rust/ast/rust-ast-collector.cc
@@ -639,7 +639,10 @@ TokenCollector::visit (TypePathSegmentGeneric &segment)
   //    `<` `>`
   //    | `<` ( GenericArg `,` )* GenericArg `,`? `>`
   describe_node (std::string ("TypePathSegmentGeneric"), [this, &segment] () {
-    auto ident_segment = segment.get_ident_segment ();
+    auto ident_segment
+      = segment.is_lang_item ()
+	  ? PathIdentSegment ("LANG_ITEM", segment.get_locus ())
+	  : segment.get_ident_segment ();
     auto id = ident_segment.as_string ();
     push (Rust::Token::make_identifier (ident_segment.get_locus (),
 					std::move (id)));