package/gzip: add upstream patch to fix build for aarch64

Since Buildroot commit [1] (package/gzip: bump version to 1.15),
gzip fails at build time for Aarch64 with the error:

  In file included from gzip.c:61:
  gzip.h:120:21: error: expected ')' before '+' token
    120 | #  define head (prev+WSIZE)  /* hash head (see deflate.c) */
        |                     ^

The issue was introduced by upstream commit [2], included in
gzip 1.15.

This commit fixes the issue by adding the patch
0001-build-avoid-failure-to-build-on-linux-aarch64.patch
from upstream commit [3], not yet included in a
gzip release.

Fixes:
https://autobuild.buildroot.org/results/3795b23407021e9fbaaf44c9319085c30d7511c1/

[1] fe21a5fe30
[2] https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=ede0a8888a4d3d0750e1651e01f198e2faab5d59
[3] https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=b4ed8e73401968bcad749afb0e636dd3ec205ca7

Reported-by: Waldemar Brodkorb <wbx@openadk.org>
Link: https://lore.kernel.org/buildroot/asJEBMQpD2FYJql2@waldemar-brodkorb.de/
Signed-off-by: Peter Seiderer <ps.report@gmx.net>
[Julien: add info in commit log]
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/gzip/0001-build-avoid-failure-to-build-on-linux-aarch64.patch

@@ -0,0 +1,43 @@
+From 56b57a937db747c3f94746379c4d95d8a787bde4 Mon Sep 17 00:00:00 2001
+From: Jim Meyering <meyering@meta.com>
+Date: Mon, 21 Sep 2026 01:42:18 -0700
+Subject: [PATCH] build: avoid failure to build on linux aarch64
+
+* gzip.c: Include gzip.h only after all system headers.
+gzip.h's "head" definition affected a subsequent signal.h-
+included system struct member named "head".
+Reported by Adam Sampson in https://bugs.gnu.org/81904
+
+Upstream: https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=b4ed8e73401968bcad749afb0e636dd3ec205ca7
+Signed-off-by: Peter Seiderer <ps.report@gmx.net>
+---
+ gzip.c | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/gzip.c b/gzip.c
+index 220f6fc..6c0af7f 100644
+--- a/gzip.c
++++ b/gzip.c
+@@ -58,7 +58,6 @@ static char const license_msg[] =
+ 
+ #include "tailor.h"
+ 
+-#include "gzip.h"
+ #include "lzw.h"
+ #include "revision.h"
+ #include "version.h"
+@@ -99,6 +98,11 @@ static char const license_msg[] =
+ #  include <utimens.h>
+ #endif
+ 
++/* Include this only after all system headers. Otherwise, its definition
++   of "head" conflicts with member names in linux-headers 7.2.6's
++   asm/sigcontext.h pulled in via <signal.h>.  */
++#include "gzip.h"
++
+ #ifndef MAX_PATH_LEN
+ #  define MAX_PATH_LEN   1024 /* max pathname length */
+ #endif
+-- 
+2.55.0
+