Document more obsolete syntax #4171

Job	Run time
macos-static	3m 11s
cygwin (32)	5m 31s
windows (32, windows-2019)	4m 45s
cygwin (64)	5m 29s
unix (ubuntu-20.04, g++, make)	5m 40s
windows (32, windows-2022)	6m 11s
unix (ubuntu-20.04, g++, cmake)	6m 1s
windows (64, windows-2019)	4m 52s
unix (ubuntu-20.04, clang++, make)	6m 5s
windows-mingw-build (32)	1m 7s
windows (64, windows-2022)	5m 54s
unix (ubuntu-20.04, clang++, cmake)	6m 12s
windows-mingw-build (64)	1m 3s
unix (ubuntu-22.04, g++, make)	6m 13s
unix (ubuntu-22.04, g++, cmake)	6m 19s
unix (ubuntu-22.04, clang++, make)	4m 15s
unix (ubuntu-22.04, clang++, cmake)	4m 20s
unix (macos-14, clang++, make)	5m 41s
unix (macos-14, clang++, cmake)	5m 52s
windows-mingw-testing (windows-2019, 32)	4m 33s
windows-mingw-testing (windows-2019, 64)	3m 50s
windows-mingw-testing (windows-2022, 32)	5m 17s
windows-mingw-testing (windows-2022, 64)	4m 13s
	1h 52m 34s

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