Emulate "install -D" behavior as it is not available on OS X.
Emulate "install -D" behavior as it is not available on OS X.

nivertech/libsnark,gstew5/libsnark,jl777/libsnark,wyrdmantis/libsnark,martindale/libsnark,gstew5/libsnark,nivertech/libsnark,jl777/libsnark,wyrdmantis/libsnark,gstew5/libsnark,jl777/libsnark,martindale/libsnark,nivertech/libsnark,wyrdmantis/libsnark,martindale/libsnark