[gcc r15-3643] c++: avoid init_priority warning in system header

[Jason Merrill]

https://gcc.gnu.org/g:8b5e54712a1efd1bf0c08a3d9523ab0c265e344a

commit r15-3643-g8b5e54712a1efd1bf0c08a3d9523ab0c265e344a
Author: Jason Merrill <jason@redhat.com>
Date:   Sat Sep 14 11:46:22 2024 +0200

    c++: avoid init_priority warning in system header
    
    We don't want a warning about a reserved init_priority in a system header
    even with -Wsystem-headers.
    
    gcc/cp/ChangeLog:
    
            * tree.cc (handle_init_priority_attribute): Check
            in_system_header_at.

Diff:
---
 gcc/cp/tree.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
index 99088da9cee0..f43febed124c 100644
--- a/gcc/cp/tree.cc
+++ b/gcc/cp/tree.cc
@@ -5196,7 +5196,8 @@ handle_init_priority_attribute (tree* node,
 
   /* Check for init_priorities that are reserved for
      language and runtime support implementations.*/
-  if (pri <= MAX_RESERVED_INIT_PRIORITY)
+  if (pri <= MAX_RESERVED_INIT_PRIORITY
+      && !in_system_header_at (input_location))
     {
       warning
 	(0, "requested %<init_priority%> %i is reserved for internal use",