cmSystemTools: Implement GetRealPath on Windows
Use cm::PathResolver
's RealPath
variant to normalize paths,
look up their on-disk case, and resolve symlinks, but without
resolving subst
drives on Windows.
Also drop GetRealPathResolvingWindowsSubst
now that GetRealPath
works on Windows.
Fixes: #17206 (closed)
Issue: #18033 (closed)