tree c77bb650b2d1fc8b8b781c395d576a0b0d748c13
parent 6b618828f1835f5b599ca2ae46a7b7a19e873cd4
author dan sinclair <dsinclair@chromium.org> 1695689940 +0000
committer Dawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com> 1695689940 +0000

[ir] Make root block always exist

Previously the `root_block` only existed if it had content. This CL
changes the IR to always create the root block. This removes a potential
tripping hazzard of getting a `nullptr` root block. It also removes the
possibilty of accidentally creating the root block during transformation
by calling `RootBlock()` on the builder.

Bug: tint:1718
Change-Id: I62a6cd605cf774b4645911b7dde9df832f539004
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/153421
Reviewed-by: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: dan sinclair <dsinclair@chromium.org>