Thread UTF-16 string input through JSON, script parsing, Date parsing,
Intl option parsing, Temporal parsing, and the helper library boundaries
that feed those parsers. Preserve ASCII fast paths where the source data
is known to be ASCII.
Move the remaining LibJS primitive string users to UTF-16 views and
strings. Remove the primitive string UTF-8 accessors and byte-string
coercion paths so new callers cannot rely on the old storage model.
Keep primitive string storage in Utf16String and remove the UTF-8
storage path from PrimitiveString. ASCII strings still use compact
Utf16String ASCII storage, while UTF-16 becomes the only owned
representation.
This is an editorial change in the ECMA-402 spec. See:
https://github.com/tc39/ecma402/commit/a2beb66
We implement this change by introducing a virtual interface that all
Intl "service" objects must implement. A future patch will make use of
the virtualized RelevantExtensionKeys and ResolutionOptionDescriptors
accessors, and we will need to be able to use those slots from a generic
instance type.
This is a normative change in the ECMA-402 spec. See:
https://github.com/tc39/ecma402/commit/7508197
In our implementation, we don't have the affected AOs directly, as we
delegate to ICU. So instead, we must ensure we provide ICU a locale with
the relevant extension keys present.
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
