Revert "[turbofan] Temporarily disable OSR for performance data"

This reverts commit 84853ad1.

Reason for revert: Blocking LKGR because of Arm timeouts, see
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm%20-%20sim%20-%20debug/16047

Original change's description:
> [turbofan] Temporarily disable OSR for performance data
> 
> Just set the flag --use-osr to false by default.
> If it's set to true on the command line, then it'll be on.
> 
> I'd like to get some performance metrics on various tests spread
> throughout our performance bot infrastructure.
> 
> Change-Id: I1ebc33264505af080901e531dca625452880f81b
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1558089
> Reviewed-by: Maya Lekova <mslekova@chromium.org>
> Commit-Queue: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#60693}

TBR=mvstanton@chromium.org,mslekova@chromium.org

Bug: chromium:950934

Change-Id: I6c713f33f491bda49cd1d1d2f155f1971217089e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1559859Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60719}

src/flag-definitions.h

@@ -521,7 +521,7 @@ DEFINE_BOOL(inline_accessors, true, "inline JavaScript accessors")
 DEFINE_BOOL(inline_into_try, true, "inline into try blocks")
 DEFINE_BOOL(turbo_inline_array_builtins, true,
             "inline array builtins in TurboFan code")
-DEFINE_BOOL(use_osr, false, "use on-stack replacement")
+DEFINE_BOOL(use_osr, true, "use on-stack replacement")
 DEFINE_BOOL(trace_osr, false, "trace on-stack replacement")
 DEFINE_BOOL(analyze_environment_liveness, true,
             "analyze liveness of environment slots and zap dead values")