[gcc r13-4697] rust: Fix up aarch64-linux bootstrap [PR106072]

[gcc r13-4697] rust: Fix up aarch64-linux bootstrap [PR106072]

[Jakub Jelinek]

https://gcc.gnu.org/g:95dc11475dac06b5eecd904079de8aa94827a36a

commit r13-4697-g95dc11475dac06b5eecd904079de8aa94827a36a
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Wed Dec 14 11:35:22 2022 +0100

    rust: Fix up aarch64-linux bootstrap [PR106072]
    
    Bootstrap fails on aarch64-linux and some other arches with:
    .../gcc/rust/parse/rust-parse-impl.h: In member function ‘Rust::AST::ClosureParam Rust::Parser<ManagedTokenSource>::parse_closure_param() [with ManagedTokenSource = Rust::Lexer]’:
    .../gcc/rust/parse/rust-parse-impl.h:8916:49: error: ‘this’ pointer is null [-Werror=nonnull]
    The problem is that while say on x86_64-linux the side-effects in the
    arguments are evaluated from last argument to first, on aarch64-linux
    it is the other way around, from first to last.  The C++ I believe even
    in C++17 makes the evaluation of those side-effects unordered
    (indeterminately sequenced with no interleaving), so that is fine.
    But, when the call in return statement is evaluated from first to
    last, std::move (pattern) happens before pattern->get_locus () and
    the former will make pattern (std::unique_ptr) a wrapper object around
    nullptr, so dereferencing it later to call get_locus () on it is invalid.
    
    2022-12-14  Jakub Jelinek  <jakub@redhat.com>
    
            PR rust/106072
            * parse/rust-parse-impl.h (parse_closure_param): Store
            pattern->get_locus () in a temporary before std::move (pattern) is
            invoked.

Diff:
---
 gcc/rust/parse/rust-parse-impl.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/parse/rust-parse-impl.h b/gcc/rust/parse/rust-parse-impl.h
index bbcbab27505..e555d93dca3 100644
--- a/gcc/rust/parse/rust-parse-impl.h
+++ b/gcc/rust/parse/rust-parse-impl.h
@@ -8912,8 +8912,9 @@ Parser<ManagedTokenSource>::parse_closure_param ()
 	}
     }
 
-  return AST::ClosureParam (std::move (pattern), pattern->get_locus (),
-			    std::move (type), std::move (outer_attrs));
+  Location loc = pattern->get_locus ();
+  return AST::ClosureParam (std::move (pattern), loc, std::move (type),
+			    std::move (outer_attrs));
 }
 
 // Parses a grouped or tuple expression (disambiguates).