This fixes constructors for structures that contain padding members
due to explicit layout attributes.
Also fix one test that was wrongly using an identity type constructor
for a structure.
Fixed: tint:853
Change-Id: I0a3e84fcd7c6a7f2ad92a4970ed11378e6ce2465
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/53240
Auto-Submit: James Price <jrprice@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>