With this change, we now have ~1200 CellAllocators across both LibJS and
LibWeb in a normal WebContent instance.
This gives us a minimum heap size of 4.7 MiB in the scenario where we
only have one cell allocated per type. Of course, in practice there will
be many more of each type, so the effective overhead is quite a bit
smaller than that in practice.
I left a few types unconverted to this mechanism because I got tired of
doing this. :^)
These lambdas were marked mutable as they captured a Ptr wrapper
class by value, which then only returned const-qualified references
to the value they point from the previous const pointer operators.
Nothing is actually mutating in the lambdas state here, and now
that the Ptr operators don't add extra const qualifiers these
can be removed.
This was an oversight from when I converted PendingResponse and various
other classes from being ref-counted to GC-allocated last minute - no
one takes care to keep all of them alive. Some are on the stack, and
some might be captured in another PendingResponse's JS::SafeFunction,
but ultimately, we need a better solution.
Since a PendingResponse is *always* the result of someone having created
a Request, let's just let that keep a list of each PendingResponse that
has been created for it, and visit them until they are resolved. After
that, they can be GC'd with no complaints.
This implements the following operations from section 4 of the Fetch
spec (https://fetch.spec.whatwg.org/#fetching):
- Fetch
- Main fetch
- Fetch response handover
- Scheme fetch
- HTTP fetch
- HTTP-redirect fetch
- HTTP-network-or-cache fetch (without caching)
It does *not* implement:
- HTTP-network fetch
- CORS-preflight fetch
Instead, we let ResourceLoader handle the actual networking for now,
which isn't ideal, but certainly enough to get enough functionality up
and running for most websites to not complain.
