buildbot: Update to newer MinGW gcc 9.2

.gitlab-ci.yml

@@ -239,13 +239,13 @@ build:fedora-24:
 ##
 
 .generic_win_template: &generic_win_template
-  image: ubuntu:xenial
+  image: ubuntu:bionic
   before_script:
     - apt-get update -y
-    - apt-get install -y p7zip-full wget unzip git cmake gettext
-    - wget http://minetest.kitsunemimi.pw/mingw-w64-${WIN_ARCH}_7.1.1_ubuntu14.04.7z -O mingw.7z > /dev/null
+    - apt-get install -y wget xz-utils unzip git cmake gettext
+    - wget -q http://minetest.kitsunemimi.pw/mingw-w64-${WIN_ARCH}_9.2.0_ubuntu18.04.tar.xz -O mingw.tar.xz
     - sed -e "s|%PREFIX%|${WIN_ARCH}-w64-mingw32|" -e "s|%ROOTPATH%|/usr/${WIN_ARCH}-w64-mingw32|" < util/travis/toolchain_mingw.cmake.in > ${TOOLCHAIN_OUTPUT}
-    - 7z x -y -o/usr mingw.7z > /dev/null
+    - tar -xaf mingw.tar.xz -C /usr
 
 .build_win_template: &build_win_template
   <<: *generic_win_template

util/travis/before_install.sh

@@ -17,17 +17,13 @@ if [[ $PLATFORM == "Unix" ]] || [[ ! -z "${CLANG_TIDY}" ]]; then
 		install_macosx_deps
 	fi
 elif [[ $PLATFORM == "Win32" ]]; then
-	sudo apt-get update
-	sudo apt-get install p7zip-full
-	wget http://minetest.kitsunemimi.pw/mingw-w64-i686_7.1.1_ubuntu14.04.7z -O mingw.7z
+	wget http://minetest.kitsunemimi.pw/mingw-w64-i686_9.2.0_ubuntu18.04.tar.xz -O mingw.tar.xz
 	# buildwin32.sh detects the installed toolchain automatically
-	sudo 7z x -y -o/usr mingw.7z
+	sudo tar -xaf mingw.tar.xz -C /usr
 elif [[ $PLATFORM == "Win64" ]]; then
-	sudo apt-get update
-	sudo apt-get install p7zip-full
-	wget http://minetest.kitsunemimi.pw/mingw-w64-x86_64_7.1.1_ubuntu14.04.7z -O mingw.7z
+	wget http://minetest.kitsunemimi.pw/mingw-w64-x86_64_9.2.0_ubuntu18.04.tar.xz -O mingw.tar.xz
 	sed -e "s|%PREFIX%|x86_64-w64-mingw32|" \
 		-e "s|%ROOTPATH%|/usr/x86_64-w64-mingw32|" \
 		< util/travis/toolchain_mingw.cmake.in > util/buildbot/toolchain_mingw64.cmake
-	sudo 7z x -y -o/usr mingw.7z
+	sudo tar -xaf mingw.tar.xz -C /usr
 fi