Unifies GetSharedFunctionForStreamedScript with GetSharedFunctionForScript
so that both share a more similar API and some common code can be moved to
common helpers.

Introduces a Compiler::ScriptDetails struct to hold script meta-data
used to build new script objects.

BUG=v8:5203

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I3e6b4cd50da9bb92ef5a2bfd666a09b3619c34a4
Reviewed-on: https://chromium-review.googlesource.com/924189
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51438}