mesa: Support GL_VERTEX_ATTRIB_ARRAY_INTEGER in GL 3.0 contexts.

According to Table 6.8 (Page 348) in the OpenGL 3.0 specification,
glGetVertexAttribiv supports GL_VERTEX_ATTRIB_ARRAY_INTEGER.

NOTE: This is a candidate for the 8.0 branch.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/main/varray.c

@@ -555,7 +555,7 @@ get_vertex_array_attrib(struct gl_context *ctx, GLuint index, GLenum pname,
    case GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING_ARB:
       return array->BufferObj->Name;
    case GL_VERTEX_ATTRIB_ARRAY_INTEGER:
-      if (ctx->Extensions.EXT_gpu_shader4) {
+      if (ctx->VersionMajor >= 3 || ctx->Extensions.EXT_gpu_shader4) {
          return array->Integer;
       }
       goto error;