[snapshot] Flip --lazy-handler-deserialization

This enables lazy bytecode handler deserialization by default.

Design doc: http://goo.gl/QxZBL2

TBR=hablich@chromium.org

Bug: v8:6624
Change-Id: I89a17e16a4ee18ee1bfca75a1d61f7a11cdc211f
Reviewed-on: https://chromium-review.googlesource.com/776836Reviewed-by: Michael Hablich <hablich@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49526}

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)