Any struct which is used as the store type of a buffer variable needs
to have a block decoration. If that struct is nested inside an array
or another struct, we wrap it inside another struct first.
This removes the SPIR-V backend's reliance on the [[block]] attribute,
which will soon be deprecated and removed.
Bug: tint:1324
Change-Id: Ib6ad54f24a3e4a090da9faeed699f266abcb66ba
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/72082
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>