Allow getting size of dynamic format arg store (#4270) #7708

Job	Run time
mingw (mingw64)	4m 1s
build (windows-2019, Win32, v142, 17, Debug)	1m 45s
mingw (ucrt64)	4m 21s
build (windows-2019, Win32, v142, 17, Release)	2m 35s
build (windows-2019, Win32, v142, 17, -DBUILD_SHARED_LIBS=ON, Debug)	1m 6s
build (windows-2019, Win32, v142, 17, -DBUILD_SHARED_LIBS=ON, Release)	2m 42s
build (windows-2019, x64, v141, 14, Debug)	1m 50s
build (windows-2019, x64, v141, 14, Release)	2m 35s
build (windows-2019, x64, v141, 17, Debug)	1m 36s
build (windows-2019, x64, v141, 17, Release)	2m 26s
build (windows-2019, x64, v142, 17, Debug)	1m 34s
build (windows-2019, x64, v142, 17, Release)	2m 38s
build (windows-2019, x64, v142, 17, -DBUILD_SHARED_LIBS=ON, Debug)	1m 25s
build (windows-2019, x64, v142, 17, -DBUILD_SHARED_LIBS=ON, Release)	2m 3s
build (windows-2019, x64, v142, 20, Debug)	2m 11s
build (windows-2019, x64, v142, 20, Release)	2m 51s
build (windows-2022, x64, v143, Debug, 20)	2m 28s
	40m 7s

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