The original idea of returning pointers is that handles can be moved.
The problem is that the implementation didn't take that in mind and made
everything harder to work with. This commit drops pointer to handles and
returns the handles themselves. While it is still true that handles can
be invalidated, this way we get an old handle instead of a dangling
pointer.
This problem can be solved in the future with sparse buffers.
This currently only supports quad arrays and u8 indices.
In the future we can remove quad arrays with a table written from the
CPU, but this was used to bootstrap the other passes helpers and it
was left in the code.
The blob code is generated from the "shaders/" directory. Read the
instructions there to know how to generate the SPIR-V.
