toolchain: gdb: Update to version 15.2

See news file for changes:
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob_plain;f=gdb/NEWS;hb=gdb-15.1-release

This requires a C++17 compiler compatible compiler.

Link: https://github.com/openwrt/openwrt/pull/16665
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

toolchain/gdb/Makefile

@@ -7,12 +7,12 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=gdb
-PKG_VERSION:=14.1
+PKG_VERSION:=15.2
 PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=@GNU/gdb
-PKG_HASH:=d66df51276143451fcbff464cc8723d68f1e9df45a6a2d5635a54e71643edb80
+PKG_HASH:=83350ccd35b5b5a0cba6b334c41294ea968158c573940904f00b92f76345314d
 PKG_CPE_ID:=cpe:/a:gnu:gdb
 GDB_DIR:=$(PKG_NAME)-$(PKG_VERSION)
 

toolchain/gdb/patches/120-fix-compile-flag-mismatch.patch

@@ -1,6 +1,6 @@
 --- a/gdbserver/configure
 +++ b/gdbserver/configure
-@@ -2674,7 +2674,7 @@ $as_echo "$as_me: error: \`$ac_var' was
+@@ -2698,7 +2698,7 @@ $as_echo "$as_me: error: \`$ac_var' was
        ac_cache_corrupted=: ;;
      ,);;
      *)