Previously, unbuffered requests were only available as a special mode
for EventSource. With this change, they are enabled by default, which
means chunks can be read from the stream as soon as they arrive.
This unlocks some interesting possibilities, such as starting to parse
HTML documents before the entire response has been received (that, in
turn, allows us to initiate subresource fetches earlier or begin
executing scripts sooner), or start rendering videos before they are
fully downloaded.
Co-authored-by: Timothy Flynn <trflynn89@pm.me>
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
