Vulkan: Enable VK_KHR_bind_memory2 extension Don't assume support for VK_KHR_bind_memory2, enable the extension, if supported, during device creation. Also initialize all required extension functions for the memory allocator. Bug: angleproject:4966 Change-Id: I878939fb3324723675a2b7dec18ab453b2a9fc77 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2359529 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>