Undefine bool and vector after including altivec.h (#46179)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/41261
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46179
Reviewed By: bdhirsh
Differential Revision: D24258470
Pulled By: glaringlee
fbshipit-source-id: f9d3589a30ed396cb88404d3471788aed8dea237
