[nci] Imply feedback collection in generic lowering from nci

At this point in development, this is a reasonable config for the nci
test variant.

--turbo-nci currently disables some compiler phases and avoids
embedded context-dependent constants.
--turbo-collect-feedback-in-generic-lowering enables full feedback
collection in generic lowering.

I'm keeping the two as separate flags for now since it can be
interesting to benchmark --turbo-nci both with- and without feedback
collection.

Bug: v8:8888
Change-Id: I678baeb0ed051b158ac0634f00de9b6a55f87e09
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2247770
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68411}

src/flags/flag-definitions.h

@@ -658,6 +658,9 @@ DEFINE_INT(reuse_opt_code_count, 0,
 // Native context independent (NCI) code.
 DEFINE_BOOL(turbo_nci, false,
             "enable experimental native context independent code.")
+// TODO(v8:8888): Temporary until NCI caching is implemented or
+// feedback collection is made unconditional.
+DEFINE_IMPLICATION(turbo_nci, turbo_collect_feedback_in_generic_lowering)
 DEFINE_BOOL(turbo_nci_as_highest_tier, false,
             "replace default TF with NCI code as the highest tier for testing "
             "purposes.")