This commit changes the build process in a way that preserves already
registered ops in the snapshot. This allows us to skip creating hundreds of
"v8::String" on each startup, but sadly there is still some op registration
going on startup (however we're registering 49 ops instead of >200 ops).
This situation could be further improved, by moving some of the ops
from "runtime/" to a separate extension crates.
---------
Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>