There were some cases that were not yet contemplated on machine graph
verifier.

Also, there is some work to be done to create a Compressed HeapConstant.
Until that happens, we have to ignore HeapConstants for
DecompressionElimination's reductions.

Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:8977, v8:7703, v8:9298
Change-Id: I9de8dd4272866830807a8d88e625e863fb5f1d0d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1632209
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61892}