Question about developing for std::filesystem

[Adam Wood]

Hello everyone,
I am currently working on a patch to add symlink support on Windows. I
am currently only changing files in the c++17 folder (with the
exception of ops_common.h in filesystem folder). I have three
questions:
1. Should I make the same changes to the equivalent files in the
filesystem folder as well?
2. Are the std::filesystem tests using the standard c++17 filesystem
library or the gnu one?
3. What is the difference between "execution test" and "(test for
excess errors)" in the testsuite?

Thanks,
Adam Wood.