Diamond patterns need to be chained to the current control node. This
was not done consistently in wasm code, particularly the parts
implementing asm-js specific instructions.

Additionally, the graph structure for BuildI32AsmjsDivS is improved.

Change-Id: I4a17e431b5795c197bf56dd034ff5e7d95dd6db0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2578982Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71677}