Validate renderability of texture formats.

Change-Id: I49c0f7b78a131c0d78c2cfb207bb3019b2b93a15
Reviewed-on: https://swiftshader-review.googlesource.com/5129
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>