Added pureInteger member to VertexAttribute in order
to keep track of whether the attrib was set using
glVertexAttribIPointer or glVertexAttribPointer and
properly return that state when querying
GL_VERTEX_ATTRIB_ARRAY_INTEGER.

Fixes dEQP-GLES3.functional.state_query.shader.vertex_attrib_integer

Change-Id: Ie6cfcd2008f7abb61d457a41124600fe7cea229a
Reviewed-on: https://swiftshader-review.googlesource.com/14828Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>