[gcc r13-2870] fix assert in __deregister_frame_info_bases

[Thomas Neumann <tneumann@gcc.gnu.org>]

https://gcc.gnu.org/g:386ebf75f4c0342b1f823f4e4aba07abda3288d1

commit r13-2870-g386ebf75f4c0342b1f823f4e4aba07abda3288d1
Author: Thomas Neumann <tneumann@users.sourceforge.net>
Date:   Fri Sep 23 15:57:13 2022 +0200

    fix assert in __deregister_frame_info_bases
    
    When using the atomic fast path deregistering can fail during
    program shutdown if the lookup structures are already destroyed.
    The assert in __deregister_frame_info_bases takes that into
    account. In the non-fast-path case however is not aware of
    program shutdown, which caused a compiler error on such platforms.
    We fix that by introducing a constant for in_shutdown in
    non-fast-path builds.
    We also drop the destructor priority, as it is not supported on
    all platforms and we no longer rely upon the priority anyway.
    
    libgcc/ChangeLog:
            * unwind-dw2-fde.c: Introduce a constant for in_shutdown
            for the non-fast-path case. Drop destructor priority.

Diff:
---
 libgcc/unwind-dw2-fde.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libgcc/unwind-dw2-fde.c b/libgcc/unwind-dw2-fde.c
index d237179f4ea..3c0cc654ec0 100644
--- a/libgcc/unwind-dw2-fde.c
+++ b/libgcc/unwind-dw2-fde.c
@@ -51,7 +51,7 @@ static struct btree registered_frames;
 static bool in_shutdown;
 
 static void
-release_registered_frames (void) __attribute__ ((destructor (110)));
+release_registered_frames (void) __attribute__ ((destructor));
 static void
 release_registered_frames (void)
 {
@@ -67,6 +67,8 @@ static void
 init_object (struct object *ob);
 
 #else
+/* Without fast path frame deregistration must always succeed.  */
+static const int in_shutdown = 0;
 
 /* The unseen_objects list contains objects that have been registered
    but not yet categorized in any way.  The seen_objects list has had