The language server needs Torque compilation artifacts like
declarables for more advanced features. This CL moves the GlobalContext
into the LanguageServerData class when Torque compilation finishes, to
preserve all the compiler data.

Additionally, all declarables are split up by source id. This makes
providing all symbols of a file easier.

R=tebbi@chromium.org

Bug: v8:8880
Change-Id: I424d1ddc04fcd18934f76a736900bc5d08261c07
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1601132
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61462}