Related deqp tests: texturegrad, textureprojgrad

Change-Id: I17529ed426c29bc1dec48fb7ac939c29caeeaf07
Reviewed-on: https://swiftshader-review.googlesource.com/5420Tested-by: Meng-Lin Wu <marleymoo@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>