visibility macro #1048

Job	Run time
clang-sanitizers (,thread)	11m 11s
linux-compiler-compat (clang-3)	9m 47s
clang-sanitizers (,address,undefined)	10m 13s
linux-shared-libs	9m 37s
linux-compiler-compat (clang-6)	10m 35s
linux-compiler-compat (clang-8)	10m 56s
linux-compiler-compat (clang-9)	10m 27s
linux-compat (manylinux1-x64)	9m 34s
linux-compiler-compat (clang-10)	10m 20s
windows	11m 24s
linux-compat (manylinux1-x86)	9m 30s
linux-compiler-compat (clang-11)	10m 19s
linux-compat (manylinux2014-x64)	10m 0s
linux-compiler-compat (gcc-4.8)	9m 15s
linux-compat (manylinux2014-x86)	9m 41s
linux-compiler-compat (gcc-5)	10m 0s
windows-app-verifier	12m 47s
linux-compat (al2-x64)	9m 55s
linux-compiler-compat (gcc-6)	9m 53s
linux-compat (fedora-34-x64)	9m 54s
linux-compiler-compat (gcc-7)	9m 42s
linux-compat (opensuse-leap)	10m 42s
linux-compiler-compat (gcc-8)	10m 27s
linux-compat (rhel8-x64)	9m 52s
windows-shared-libs	11m 38s
windows-vc14 (x86)	9m 43s
windows-vc14 (x64)	15m 47s
downstream	10m 0s
osx	11m 0s
	5h 4m 9s

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