This also precomputes "declares parameter containing sloppy eval" and reorders
fields for better packing.

Change-Id: I598ed658f79e7d83f6b844236fc60518d9cf9f26
Reviewed-on: https://chromium-review.googlesource.com/c/1267940Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56439}