[snapshot] Flip --lazy-handler-deserialization

Flip this for a day or two to gather perf bot results & stability
issues. Results will be collected in https://crbug.com/782637.

TBR=hablich@chromium.org

Bug: v8:6624, chromium:782637
Change-Id: I70eb5d6287d4723f935715ef80d9ba129dc282f0
Reviewed-on: https://chromium-review.googlesource.com/758375Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49222}

src/flag-definitions.h

@@ -960,7 +960,7 @@ DEFINE_VALUE_IMPLICATION(runtime_call_stats, runtime_stats, 1)
 // snapshot-common.cc
 DEFINE_BOOL(lazy_deserialization, true,
             "Deserialize code lazily from the snapshot.")
-DEFINE_BOOL(lazy_handler_deserialization, false,
+DEFINE_BOOL(lazy_handler_deserialization, true,
             "Deserialize bytecode handlers lazily from the snapshot.")
 DEFINE_IMPLICATION(lazy_handler_deserialization, lazy_deserialization)
 DEFINE_IMPLICATION(future, lazy_handler_deserialization)