The change implements copy non-zero mip level for 3D textures
on D3D12 when the texture has multiple mip levels. The texture
size on level 0 can be either 256-byte aligned or 256-byte
unaligned(its size is non-power-of-two).
Bug: dawn:547
Change-Id: I8ed74fa587cfd814e7f526173dcb653d0a252a1e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/51201
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Yunchao He <yunchao.he@intel.com>
e5b9903cc1