C++ Patch to support C++17 filesystem namespace calls
requested to merge chris/rtems-source-builder:46-add-std-filesystem-chdir-and-mkdir-support-to-libstdc-v3 into main
Summary
This patch is the patch posted by @sebhub to #46 to add support C++17 filesystem namespace calls. I have added the needed defines to enable the needed functionality.
I have not sent this patch to any GCC lists. I am fine with the final patch to gcc replaceing this one.The putpse of this MR is to have the functionality enabled for %6.1.
Closes #46