PPC features on V8 are currently only enabled by checking the cpu
type (i.e if >= powerX then set a feature as available).
This CL bypasses the feature list and simply checks if the cpu
type is >= a specific type required by certain instructions.

Specific feature checks (such as FPU) can always be added back to the
list if needed.

Change-Id: Ic7d1f1375c28da507f96f93f879859ef3dbfe512
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3048971
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Reviewed-by: Junliang Yan <junyan@redhat.com>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75923}