Vulkan linear memory allocator. (#48569)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/48569
Test Plan: Imported from OSS
Reviewed By: SS-JIA
Differential Revision: D25277091
Pulled By: AshkanAliabadi
fbshipit-source-id: 0530832ce61432237976088cb72a8b7c3aee949c
