By generating a helper function for these, we can keep the atomic expression pre-statement-free. This can help prevent for-loops from being transformed into while loops, which can upset FXC.
We can't do the same for workgroup storage atomics, as the InterlockedXXX() methods have the workgroup-storage expression as the first argument, and I'm not aware of any way to make a user-declared parameter be `groupshared`.
Change-Id: I8669127a58dc9cae95ce316523029064b5c9b5fa
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/57462
Commit-Queue: James Price <jrprice@google.com>
Auto-Submit: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: James Price <jrprice@google.com>