Updates to symlinking for Windows (#34701)

* Support hardlinks/junctions on Windows systems without developer
  mode enabled
  * Generally, use of llnl.util.symlink.symlink is preferred over
    os.symlink since it handles this automatically
* Generally an error is now reported if a user attempts to create a
  symlink to a file that does not exist (this was previously allowed
  on Linux/Mac).
  * One exception to this: when Spack installs files from the source
    into their final prefix, dangling symlinks are allowed (on
    Linux/Mac - Windows does not allow this in any circumstance).
    The intent behind this is to avoid generating failures for
    installations on Linux/Mac that were succeeding before.
* Because Windows is strict about forbidding dangling symlinks,
  `traverse_tree` has been updated to skip creating symlinks if they
  would point to a file that is ignored. This check is not
  transitive (i.e., a symlink to a symlink to an ignored file would
  not be caught appropriately)
* Relocate function: resolve_link_target_relative_to_the_link
  (this is not otherwise modified)

Co-authored-by: jamessmillie <smillie@txcorp.com>

0 files changed, 0 insertions, 0 deletions