Mark legacy API with OBJC_PUBLIC #184

Job	Run time
Cross-build for arm-linux-gnueabihf LLVM-13 Release	1m 28s
Cross-build for aarch64-linux-gnu LLVM-13 Release	1m 7s
Cross-build for arm-linux-gnueabihf LLVM-14 Release	1m 27s
Cross-build for aarch64-linux-gnu LLVM-14 Release	1m 23s
Cross-build for arm-linux-gnueabihf LLVM-13 Debug	2m 16s
windows-2022 Release x64_x86	2m 18s
Cross-build for aarch64-linux-gnu LLVM-13 Debug	3m 3s
ubuntu-22.04 Release LLVM-13 libc++	1m 24s
windows-2022 Release x64	1m 14s
Cross-build for arm-linux-gnueabihf LLVM-14 Debug	2m 37s
ubuntu-22.04 Release LLVM-14 libc++	55s
windows-2022 Debug x64_x86	2m 11s
Cross-build for aarch64-linux-gnu LLVM-14 Debug	2m 16s
ubuntu-22.04 Release LLVM-15 libc++	36s
windows-2022 Debug x64	1m 55s
ubuntu-22.04 Release LLVM-13 libstdc++	26s
windows-2019 Release x64_x86	2m 11s
ubuntu-22.04 Release LLVM-14 libstdc++	26s
windows-2019 Release x64	2m 18s
ubuntu-22.04 Release LLVM-15 libstdc++	33s
windows-2019 Debug x64_x86	2m 17s
ubuntu-22.04 Debug LLVM-13 libc++	41s
windows-2019 Debug x64	2m 10s
ubuntu-22.04 Debug LLVM-14 libc++	49s
ubuntu-22.04 Debug LLVM-15 libc++	53s
ubuntu-22.04 Debug LLVM-13 libstdc++	37s
ubuntu-22.04 Debug LLVM-14 libstdc++	29s
ubuntu-22.04 Debug LLVM-15 libstdc++	1m 1s
ubuntu-20.04 Release LLVM-10 libc++	33s
ubuntu-20.04 Release LLVM-12 libc++	34s
ubuntu-20.04 Release LLVM-10 libstdc++	31s
ubuntu-20.04 Release LLVM-12 libstdc++	22s
ubuntu-20.04 Debug LLVM-10 libc++	39s
ubuntu-20.04 Debug LLVM-12 libc++	34s
ubuntu-20.04 Debug LLVM-10 libstdc++	1m 4s
ubuntu-20.04 Debug LLVM-12 libstdc++	49s
all-checks	1s
	46m 8s

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