WIP: Test MinGW and FFmpeg LTO #1027

Job	Run time
build-toolchain (aarch64, w64-mingw32, msvcrt)	42m 4s
build-toolchain (aarch64, w64-mingw32, ucrt)	38m 18s
build-toolchain (aarch64, pc-linux-gnu, libc)	28m 59s
build-toolchain (x86_64, w64-mingw32, msvcrt)	40m 42s
build-toolchain (x86_64, w64-mingw32, ucrt)	41m 29s
build-toolchain (x86_64, pc-linux-gnu, libc)	37m 33s
build-toolchain (x86_64, pc-cygwin, msvcrt)	26m 36s
build-ffmpeg	0s
build-openblas	0s
build-aarch64-tests	0s
build-libjpeg-turbo	0s
build-zlib	0s
execute-aarch64-tests	0s
build-libxml2	0s
build-openssl	0s
execute-ffmpeg-tests	0s
execute-libpeg-turbo-tests	0s
execute-openblas-tests	0s
execute-openssl-tests	0s
	4h 15m 41s

Provide feedback