Allow passing optimizations arguments to asv build
--------------------------------------------------
It is now possible to pass  ``-j``, ``--cpu-baseline``, ``--cpu-dispatch`` and
``--disable-optimization`` flags to ASV build when the ``--bench-compare``
argument is used.


Add gh-17284 to NumPy 1.20.0 release notes.
DOC: Add gh-17284 to NumPy 1.20.0 release notes.
