[openwrt/openwrt] toolchain: gdb: set -std=gnu17

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch openwrt-23.05:
https://git.openwrt.org/2c36ed03e5fd358ae4ad0c5935bbbc2bc20cfad6

commit 2c36ed03e5fd358ae4ad0c5935bbbc2bc20cfad6
Author: Hauke Mehrtens <hauke at hauke-m.de>
AuthorDate: Tue May 27 22:13:03 2025 +0200

    toolchain: gdb: set -std=gnu17
    
    Arch Linux updated to GCC15 which now defaults to GNU23 as the default
    instead of GNU17[1], and this breaks gdb compilation.
    
    This is fixed in more recent gdb versions.
    
    [1] https://gcc.gnu.org/gcc-15/porting_to.html#c23
    
    Link: https://github.com/openwrt/openwrt/pull/19065
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 toolchain/gdb/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/toolchain/gdb/Makefile b/toolchain/gdb/Makefile
index 474a18e95f..05f2e97331 100644
--- a/toolchain/gdb/Makefile
+++ b/toolchain/gdb/Makefile
@@ -53,6 +53,8 @@ else
   HOST_CONFIGURE_ARGS+= --without-python
 endif
 
+HOST_CFLAGS += -std=gnu17
+
 define Host/Install
 	mkdir -p $(TOOLCHAIN_DIR)/bin
 	$(INSTALL_BIN) $(HOST_BUILD_DIR)/gdb/gdb $(TOOLCHAIN_DIR)/bin/$(TARGET_CROSS)gdb