Fix PyTorch NEON compilation with gcc-7 (#50389)
Summary:
Apply sebpop patch to correctly inform optimizing compiler about side-effect of missing neon restrictions
Allow vec256_float_neon to be used even if compiled by gcc-7
Fixes https://github.com/pytorch/pytorch/issues/47098
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50389
Reviewed By: walterddr
Differential Revision: D25872875
Pulled By: malfet
fbshipit-source-id: 1fc5dfe68fbdbbb9bfa79ce4be2666257877e85f
