Change bare-symbol back to match intent

Change bare-symbol back to match intent

Also, attempt to document the intent better.
Problem reported by Alan Mackenzie (Bug#69684).
* src/data.c (Fbare_symbol): Do not signal if the SYM is a symbol
with position and symbols-with-pos-enabled is nil.  Instead,
ignore symbols-with-pos-enabled, as that was the intent.
* test/src/data-tests.el (data-tests-bare-symbol):
New test, to help prevent this bug from reoccurring.