Martin Storsjö authored Feb 01, 2020 and Janne Grunau committed Feb 10, 2020

It was already done this way for w32/64. Not doing it for w16 as it
didn't help there (and instead gave a small slowdown due to the two
setup instructions).

This gives a small speedup on in-order cores like A53.

Before:         Cortex A53     A72     A73
avg_w4_8bpc_neon:     60.9    25.6    29.0
avg_w8_8bpc_neon:    143.6    52.8    64.0
After:
avg_w4_8bpc_neon:     56.7    26.7    28.5
avg_w8_8bpc_neon:    137.2    54.5    64.4