[gcc/devel/rust/master] Fix undefined behaviour using .get on unique_ptr

[Thomas Schwinge <tschwinge@gcc.gnu.org>]

https://gcc.gnu.org/g:81c4b6989f044a45455717b752cafb96f04b768e

commit 81c4b6989f044a45455717b752cafb96f04b768e
Author: Philip Herron <philip.herron@embecosm.com>
Date:   Fri Jul 8 14:54:37 2022 +0100

    Fix undefined behaviour using .get on unique_ptr
    
    As the move semantics for AST and HIR crates are unsafe on older compilers
    we are working around this by storing the pointer into the mappings class
    this was using the get method to store the pointer. The issue for loading
    extern crates the unique_ptr goes out of scope and this the deletion code
    resulting in undefined behaviour. This changes it to call release to take
    full ownership of the pointer as we expect.

Diff:
---
 gcc/rust/util/rust-hir-map.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index 353b7cb16ed..360dabf912f 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -199,7 +199,7 @@ Mappings::insert_ast_crate (std::unique_ptr<AST::Crate> &&crate,
   rust_assert (it == ast_crate_mappings.end ());
 
   // store it
-  ast_crate_mappings.insert ({crate_num, crate.get ()});
+  ast_crate_mappings.insert ({crate_num, crate.release ()});
 
   // return the reference to it
   it = ast_crate_mappings.find (crate_num);
@@ -236,7 +236,7 @@ Mappings::insert_hir_crate (std::unique_ptr<HIR::Crate> &&crate)
 
   insert_node_to_hir (crate->get_mappings ().get_nodeid (),
 		      crate->get_mappings ().get_hirid ());
-  hir_crate_mappings.insert ({crateNum, crate.get ()});
+  hir_crate_mappings.insert ({crateNum, crate.release ()});
 
   it = hir_crate_mappings.find (crateNum);
   rust_assert (it != hir_crate_mappings.end ());