[gcc r14-8535] gccrs: forever stack: Improve resolve_path implementation

[Arthur Cohen]

https://gcc.gnu.org/g:66e8a1614e4cc9d3eb92f1288cf19a805b21ac1a

commit r14-8535-g66e8a1614e4cc9d3eb92f1288cf19a805b21ac1a
Author: Arthur Cohen <arthur.cohen@embecosm.com>
Date:   Wed Aug 23 13:50:16 2023 +0200

    gccrs: forever stack: Improve resolve_path implementation
    
    gcc/rust/ChangeLog:
    
            * resolve/rust-forever-stack.hxx: Do not copy segment when
            dereferencing iterator in `find_starting_point`.

Diff:
---
 gcc/rust/resolve/rust-forever-stack.hxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/rust/resolve/rust-forever-stack.hxx b/gcc/rust/resolve/rust-forever-stack.hxx
index 8f0ab66b18b7..642135cda854 100644
--- a/gcc/rust/resolve/rust-forever-stack.hxx
+++ b/gcc/rust/resolve/rust-forever-stack.hxx
@@ -333,7 +333,7 @@ ForeverStack<N>::find_starting_point (const std::vector<S> &segments,
 
   for (; !is_last (iterator, segments); iterator++)
     {
-      auto seg = *iterator;
+      auto &seg = *iterator;
       auto is_self_or_crate
 	= seg.is_crate_path_seg () || seg.is_lower_self_seg ();