Cannot find dotnet root on x64 darwin

[LeeDongGeon1996]

The latest version of clr-loader finds the dotnet root with literal path string. It causes the problem on x64 darwin system, which dotnet root is /usr/local/share/dotnet/x64

Before on 0.1.7, it finds with which(dotnet) so there was no problem.
Could you have a look?

clr-loader/clr_loader/util/find.py

Lines 44 to 45 in 1df0f23

	elif sys.platform == "darwin":
	dotnet_root = Path("/usr/local/share/dotnet")

---Edited

With noted on Python documentation, I'd like to suggest to check whether the system is 64-bits or not.
https://docs.python.org/3/library/platform.html#cross-platform

    if:
        # Something
        pass
    elif sys.platform == "darwin":
        if sys.maxsize > 2**32: # is_64bits
            dotnet_root = Path("/usr/local/share/dotnet/x64")
        else:
            dotnet_root = Path("/usr/local/share/dotnet")