Add rendering tests for all color formats

BUG=dawn:128

Change-Id: I32cab39e77847388a7736a51532a1b5c24a0fde7
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/8684
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Jiawei Shao <jiawei.shao@intel.com>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>

src/common/Math.h

@@ -51,6 +51,7 @@ destType BitCast(const sourceType& source) {
 }
 
 uint16_t Float32ToFloat16(float fp32);
+bool IsFloat16NaN(uint16_t fp16);
 
 float SRGBToLinear(float srgb);