Build failure on x86 linux: undefined reference to `__atomic_load'

[Luke Benes]

Rene,
> Or clang needs -latomic and gcc not.
Yes, it does. Looks like a known bug in clang:
 https://bugs.llvm.org/show_bug.cgi?id=45785

Building with "-DCMAKE_CXX_FLAGS=-latomic", resolves the undefined reference to `__atomic_load' and allows the build to complete successfully. However, it causes clang to spam 
clang-12: warning: -latomic: 'linker' input unused [-Wunused-command-line-argument]

when building.

-Luke