Add end to end tests
Fixed: tint:1026
Change-Id: I10813cbe6dc4f1bccddf9a8a29e3a249a364c051
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/59663
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>