It is recommended to map buffers once and not each time the
mapped memory is needed. This patch will map the buffer when
created and unmap the buffer when the buffer is freed.
This patch will reduce the overhead where the Vulkan driver or
the virtual memory manager needs to be accessed.
Pull Request: blender/blender#105588
This patch adds a placeholder for the vulkan backend.
When activated (`WITH_VULKAN_BACKEND=On` and `--gpu-backend vulkan`)
it might open a blender screen, but nothing should be visible as
none of the functions are implemented or otherwise crash on a nullptr.
This is expected as this is just a placeholder. The goal is to add shader compilation
+validation to this backend as one of the next steps so we can validate
changes to existing shaders on OpenGL, Metal and Vulkan at the same time.
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D16338
