Export `compiled_string` so that user can customize one #6338

Job	Run time
mingw (mingw64)	4m 14s
build (windows-2019, Win32, v142, 17, Debug)	1m 27s
mingw (ucrt64)	4m 31s
build (windows-2019, Win32, v142, 17, Release)	2m 7s
build (windows-2019, Win32, v142, 17, -DBUILD_SHARED_LIBS=ON, Debug)	1m 10s
build (windows-2019, Win32, v142, 17, -DBUILD_SHARED_LIBS=ON, Release)	2m 28s
build (windows-2019, x64, v140, 14, Debug)	1m 11s
build (windows-2019, x64, v140, 14, Release)	1m 42s
build (windows-2019, x64, v141, 17, Debug)	1m 25s
build (windows-2019, x64, v141, 17, Release)	2m 14s
build (windows-2019, x64, v142, 17, Debug)	1m 9s
build (windows-2019, x64, v142, 17, Release)	2m 21s
build (windows-2019, x64, v142, 17, -DBUILD_SHARED_LIBS=ON, Debug)	1m 34s
build (windows-2019, x64, v142, 17, -DBUILD_SHARED_LIBS=ON, Release)	2m 1s
build (windows-2019, x64, v142, 20, Debug)	1m 38s
build (windows-2019, x64, v142, 20, Release)	2m 49s
build (windows-2022, x64, v143, Debug, 20)	2m 17s
	36m 18s

Provide feedback