This is a GC-aware wrapper around AK::HashMap. Entry values are treated
as GC roots, much like the GC::RootVector we already had.
We also provide GC::OrderedRootHashMap as a convenience.
This patch adds a workaround for a Swift issue where boolean bitfields
with getters and setters in SWIFT_UNSAFE_REFERENCE types are improperly
imported, causing an ICE.
This includes a protocol for creating LibGC Heap allocated Swift
objects. Pay no attention to the Unmanaged shenanigans, they are
all behind the curtain.
This will allow us to use the GC to manage the lifetime of objects
that are not C++ objects, such as Swift objects. In the future we
could expand this cursed FFI to other languages as well.
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
