handle missing NEON vst1_*_x2 intrinsics (#44198) (#44199)
Summary:
CentOS 8 on AArch64 has vld1_* intrinsics but lacks vst1q_f32_x2 one.
This patch checks for it and handle it separately to vld1_* ones.
Fixes https://github.com/pytorch/pytorch/issues/44198
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44199
Reviewed By: seemethere
Differential Revision: D23641273
Pulled By: malfet
fbshipit-source-id: c2053c8e0427705eaeeeb82ec030925bff22623a
