deopt-unlinked.js: bytecode flushing destroys the information that
%GetDeoptCount relies on, so turn that off for this test.

cleanupsome-after-unregister.js: the function-local object {o} is
assumed to be alive throughout the function, so make sure its live
range (from the optimizing compiler's view) extends that far.

Drive-by cleanup: drop some unnecessary casting boilerplate from
Genesis::InitializeGlobal_harmony_intl_date_format_range().

Change-Id: I28617f842fe046dd0875a9a082cfc55a3a076bcf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617674
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61621}