Refactor option getting v2 #16936

Job	Run time
Arch / PyPy	2m 37s
Arch Linux	2m 33s
Ubuntu Rolling (gcc, g++)	24s
CUDA (on Arch)	2m 31s
Ubuntu Rolling (--unity=on -Ddefault_library=static, --no-unittests, gcc, g++)	1m 56s
Fedora	2m 29s
Ubuntu Rolling (-Ddefault_library=both, --no-unittests, gcc, g++)	1m 35s
Gentoo	2m 29s
Ubuntu Rolling (clang, clang++)	1m 3s
OpenSUSE	2m 34s
Ubuntu Rolling (--unity=on, --no-unittests, clang, clang++)	1m 34s
Ubuntu Bionic	2m 26s
Ubuntu Rolling (--cross ubuntu-armhf.json --cross linux-mingw-w64-64bit.json, 0, gcc, g++)	2m 18s
Ubuntu Rolling (--cross ubuntu-armhf.json --cross linux-mingw-w64-64bit.json, --unity=on, gcc, g++)	2m 18s
	28m 47s

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