Quantity.info should not be copied in ufuncs #14248

Description

Currently, .info gets copied also in operations like result = q1 + q2. This is because at the end of the addition, when taking a _new_view(), result.__array_finalize__(self) is called. That does not seem reasonable -- e.g., there is no reason the result should share the name and description of one of the arguments.

Expected behavior

Instead, result.info should just be empty.

Example

import astropy.units as u
q1 = [1., 2., 3.] * u.m
q1.info.name = 'q1'
q2 = 1.*u.cm
q2.info.name = 'q2'
result = q1+q2
result.info
name = q1
dtype = float64
unit = m
class = Quantity
n_bad = 0
length = 3

This actually is a long-standing issue, see #5047. But perhaps one can tackle them one at a time...

EDIT: the problem is that this makes operations needlessly slow; see #14244 (comment)