Add workarounds to blit a buffer to a depth/stencil texture

Works around issues on Metal Intel where CopyB2T and WriteTexture
with depth/stencil textures do not work correctly.
Fixes test failures with depth16unorm in the CTS.

Deletes UseTempTextureInStencilTextureToBufferCopy in favor of
the stencil blit. The former supposedly fixes a problem where
the stencil data is not flushed into the real stencil texture
by performing another T2T copy. This only works because the Metal
Intel backend also happens to allocate s8 as d32s8. Copying
the depth aspect as well seems to make the driver remember to
flush the data.
The stencil blit is a better fix for the problem since entirely
avoids getting the driver into a bad state where the stencil data
is not in sync.

Fixed: dawn:1389
Change-Id: If34b1d58996157036c164a5bc329e38b5e53f67a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/117910
Reviewed-by: Loko Kung <lokokung@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Austin Eng <enga@chromium.org>

src/dawn/native/opengl/DeviceGL.cpp

@@ -423,7 +423,7 @@ MaybeError Device::CopyFromStagingToBufferImpl(BufferBase* source,
 
 MaybeError Device::CopyFromStagingToTextureImpl(const BufferBase* source,
                                                 const TextureDataLayout& src,
-                                                TextureCopy* dst,
+                                                const TextureCopy& dst,
                                                 const Extent3D& copySizePixels) {
     return DAWN_UNIMPLEMENTED_ERROR("Device unable to copy from staging buffer to texture.");
 }

src/dawn/native/opengl/DeviceGL.h

@@ -75,7 +75,7 @@ class Device final : public DeviceBase {
 
     MaybeError CopyFromStagingToTextureImpl(const BufferBase* source,
                                             const TextureDataLayout& src,
-                                            TextureCopy* dst,
+                                            const TextureCopy& dst,
                                             const Extent3D& copySizePixels) override;
 
     uint32_t GetOptimalBytesPerRowAlignment() const override;