[gcc/devel/omp/gcc-16] De-duplicate '#define _GNU_SOURCE' in 'libgomp/config/linux/allocator.c'

https://gcc.gnu.org/g:dd698ab1e98fb65dde6d299b3e5655db867078a3

commit dd698ab1e98fb65dde6d299b3e5655db867078a3
Author: Thomas Schwinge <[email protected]>
Date:   Thu May 21 20:31:18 2026 +0200

    De-duplicate '#define _GNU_SOURCE' in 'libgomp/config/linux/allocator.c'
    
    Minor fix-up for commit 348874f0baac0f22c98ab11abbfa65fd172f6bdd
    "libgomp: basic pinned memory on Linux".
    
            libgomp/
            * config/linux/allocator.c: De-duplicate '#define _GNU_SOURCE'.
    
    (cherry picked from commit c6133f911ea5ae4a4df59079c6299593fdec8afc)

Diff:
---
 libgomp/config/linux/allocator.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/libgomp/config/linux/allocator.c b/libgomp/config/linux/allocator.c
index c1f50e7f59b5..de15fcebb921 100644
--- a/libgomp/config/linux/allocator.c
+++ b/libgomp/config/linux/allocator.c
@@ -51,7 +51,6 @@
    that two pinned allocations don't share the same page.  This also means
    that large allocations don't pin extra pages by being poorly aligned.  */
 
-#define _GNU_SOURCE
 #include <sys/mman.h>
 #include <unistd.h>
 #include <string.h>