Reland "Revert "Temporarily remove --concurrent-inlining from --future""

This is a reland of 6805395d, after
resolving another issue.

Original change's description:
> Revert "Temporarily remove --concurrent-inlining from --future"
>
> This reverts commit 060b9ec4, as the
> issue has been resolved.
>
> Bug: v8:7790
> Change-Id: Id8a56ad50a508eacd191f2777cc5afc0b838364f
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1700078
> Commit-Queue: Georg Neis <neis@chromium.org>
> Commit-Queue: Michael Stanton <mvstanton@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Reviewed-by: Maya Lekova <mslekova@chromium.org>
> Auto-Submit: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62713}

TBR=neis@chromium.org

Bug: v8:7790
Change-Id: Ibc5991787982197d08942eb067c83001d91050ec
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1708472Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62799}

src/flags/flag-definitions.h

@@ -453,6 +453,7 @@ DEFINE_BOOL(block_concurrent_recompilation, false,
             "block queued jobs until released")
 DEFINE_BOOL(concurrent_inlining, false,
             "run optimizing compiler's inlining phase on a separate thread")
+DEFINE_IMPLICATION(future, concurrent_inlining)
 DEFINE_BOOL(trace_heap_broker_verbose, false,
             "trace the heap broker verbosely (all reports)")
 DEFINE_BOOL(trace_heap_broker, false,