Add tests around opt links
Simplify optlink method

delete/unlink on a directory is the same operation as rmdir.
Pass the mode through the optlink method
Remove default argument from make_relative_symlink

All callers of this method now pass a mode object.
blink1: add HEAD

Closes #30577.

Signed-off-by: Brett Koonce <koonce@gmail.com>
android-sdk: 23.0.1

Closes #30578.

Signed-off-by: Brett Koonce <koonce@gmail.com>