Fixes all failures in dEQP.functional.vertex_arrays.*

In OpenGL ES 3.0, vertex attributes streams can be of a
different type from the vertex attribute in the shader.
For this reason, some conversion may be required. This
cl solves this issue by:
1) Sending the information about the vertex attribute's
   type in the shader to the vertex routine.
2) Handling this information by adding conversion where
   appropriate.

Change-Id: I04a5a34aea12684209e584aa5f15a3edfd57f956
Reviewed-on: https://swiftshader-review.googlesource.com/7254Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>