The `touch -c` command-line tool does nothing when given a broken
symlink. Fix `SystemTools::Touch` to do the same.
This was broken by commit 45db0937 (SystemTools: use PathExists where
appropriate, 2017-01-10).
The `touch -c` command-line tool does nothing when given a broken
symlink. Fix `SystemTools::Touch` to do the same.
This was broken by commit 45db0937 (SystemTools: use PathExists where
appropriate, 2017-01-10).
