Support lists for ObjC and ObjC++ standards #16649

Job	Run time
Arch Linux	20m 29s
Ubuntu Rolling (gcc, g++)	20m 17s
CUDA (on Arch)	8m 16s
Arch / PyPy	21m 18s
Ubuntu Rolling (--unity=on -Ddefault_library=static, --no-unittests, gcc, g++)	13m 35s
Fedora	20m 34s
Ubuntu Rolling (-Ddefault_library=both, --no-unittests, gcc, g++)	14m 7s
Gentoo	21m 42s
Ubuntu Rolling (clang, clang++)	22m 43s
OpenSUSE	16m 20s
Ubuntu Rolling (--unity=on, --no-unittests, clang, clang++)	15m 43s
Ubuntu Bionic	15m 7s
Ubuntu Rolling (--cross ubuntu-armhf.json --cross linux-mingw-w64-64bit.json, 0, gcc, g++)	13m 31s
Ubuntu Rolling (--cross ubuntu-armhf.json --cross linux-mingw-w64-64bit.json, --unity=on, gcc, g++)	13m 51s
	3h 57m 33s

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