This is a monster patch that turns all EventTargets into GC-allocated
PlatformObjects. Their C++ wrapper classes are removed, and the LibJS
garbage collector is now responsible for their lifetimes.
There's a fair amount of hacks and band-aids in this patch, and we'll
have a lot of cleanup to do after this.
This patch passes the options argument to process_blob_parts() and makes
use of the "convert line endings to native" algorithm when the endings
member of options (BlobPropertyBag) is set to "native".