[gcc r15-8558] gccrs: fix crash in hir dump

[Arthur Cohen]

https://gcc.gnu.org/g:3fa779425cc550afb6e18671c45dba0e21d1d273

commit r15-8558-g3fa779425cc550afb6e18671c45dba0e21d1d273
Author: Philip Herron <herron.philip@googlemail.com>
Date:   Mon Dec 2 17:38:55 2024 +0000

    gccrs: fix crash in hir dump
    
    gcc/rust/ChangeLog:
    
            * hir/rust-hir-dump.cc (Dump::visit): add missing check for no return value
    
    Signed-off-by: Philip Herron <herron.philip@googlemail.com>

Diff:
---
 gcc/rust/hir/rust-hir-dump.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/rust/hir/rust-hir-dump.cc b/gcc/rust/hir/rust-hir-dump.cc
index be785b9ebec2..2590eed19ae8 100644
--- a/gcc/rust/hir/rust-hir-dump.cc
+++ b/gcc/rust/hir/rust-hir-dump.cc
@@ -1365,7 +1365,8 @@ Dump::visit (ReturnExpr &e)
   begin ("ReturnExpr");
   do_mappings (e.get_mappings ());
 
-  visit_field ("return_expr", e.get_expr ());
+  if (e.has_return_expr ())
+    visit_field ("return_expr", e.get_expr ());
 
   end ("ReturnExpr");
 }