lose build of clang 3.9x compiler with libc++ since that appears to be missing std filesystem code
lose build of clang 3.9x compiler with libc++ since that appears to be missing std filesystem code

SophistSolutions/Stroika,SophistSolutions/Stroika,SophistSolutions/Stroika,SophistSolutions/Stroika,SophistSolutions/Stroika