Compile issue on CentOS 6 about xmrig-cuda

[xmrig]

Please show cmake output from fresh start, I fix -Ofast and size_t (by adding <cstddef> header), but this gcc version should understand std=c++11.
Thank you.

[m8522s]

-- The C compiler identification is GNU 6.3.1
-- The CXX compiler identification is GNU 6.3.1
-- Check for working C compiler: /opt/rh/devtoolset-6/root/usr/bin/cc
-- Check for working C compiler: /opt/rh/devtoolset-6/root/usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /opt/rh/devtoolset-6/root/usr/bin/c++
-- Check for working CXX compiler: /opt/rh/devtoolset-6/root/usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Looking for __builtin___clear_cache
-- Looking for __builtin___clear_cache - found
-- Found CUDA: /usr/local/cuda (found suitable version "9.1", minimum required is "8.0") 
-- Configuring done
-- Generating done
-- Build files have been written to: /usr/src/xmrig-cuda/build

[m8522s]

I also cloned the git repository locally and re-done the compilation steps. Now it compiles with out issue. Thanks for fixing.