[COMMITTED 218/220] gccrs: Add check before calling `get_trait_ref()`

[arthur . cohen]

From: Ryutaro Okada <1015ry...@gmail.com>

gcc/rust/ChangeLog:

        * hir/tree/rust-hir-visitor.cc (DefaultHIRVisitor::walk):
        Add check before calling  `get_trait_ref()`

Signed-off-by: Ryutaro Okada <1015ry...@gmail.com>
---
 gcc/rust/hir/tree/rust-hir-visitor.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/rust/hir/tree/rust-hir-visitor.cc 
b/gcc/rust/hir/tree/rust-hir-visitor.cc
index c77300aae3a..d90b50e7fe1 100644
--- a/gcc/rust/hir/tree/rust-hir-visitor.cc
+++ b/gcc/rust/hir/tree/rust-hir-visitor.cc
@@ -897,7 +897,8 @@ DefaultHIRVisitor::walk (ImplBlock &impl)
   visit_outer_attrs (impl);
   for (auto &generic : impl.get_generic_params ())
     generic->accept_vis (*this);
-  impl.get_trait_ref ().accept_vis (*this);
+  if (impl.has_trait_ref ())
+    impl.get_trait_ref ().accept_vis (*this);
   impl.get_type ().accept_vis (*this);
   if (impl.has_where_clause ())
     visit_where_clause (impl.get_where_clause ());
-- 
2.49.0