Changes the ShouldUseFullCodegen to use the flags on the literal instead
of the SharedFunctionInfo. Also moves the setting of the SFI flags based
on the literal to be in the final stage of unoptimized compilation since
they are no longer needed on the SFI during compilation. This is in
preparation to enable shared function infos to be created after
bytecode generation (to enable off-thread bytecode generation).

BUG=v8:5203, v8:6409

Change-Id: I15754979a704123b56dad9e1dfd5c3bb468b85c7
Reviewed-on: https://chromium-review.googlesource.com/570249
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46684}