In the Vulkan renderer use a vector of vertex buffers and an index for each thread
In the Vulkan renderer use a vector of vertex buffers and an index for each thread

It doesn't seem sensible to share the same vector of vertex buffers between all
threads.  This changeset creates another vector layer to address this.  Once the
first index is created by the main thread at initialisation, each thread ought
to be able to safely access their individual index.  This doesn't address the
disappearing geometry, however.

StrayLightning/aeolius,StrayLightning/aeolius,StrayLightning/aeolius