Store parser errors, source range filenames, source code filenames,
module source, and Rust parser errors as UTF-16 where they flow back
into JavaScript-visible strings. Keep byte-oriented source buffers
byte-backed.
Remove temporary PrimitiveString, ByteString, and UTF-8 detours from
JSON, RegExp, module debug logging, print formatting, and tests.
Produce JS-visible string results as UTF-16 at their source, including
numeric formatting, BigInt and BigFraction formatting, URI encoding,
console formatting, parser errors, regular expression errors, Intl and
Temporal records, LibUnicode locale boundaries, and LibWeb bindings.
Handle fractional radix formatting through the UTF-16 builder view.
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.
Primary motivation for this change is the `VERIFY(icu_success(status))`
line in `Segmenter::create()` that was failing on multiple systems and
where we had to ask people to apply a patch to even know what the error
was.
Since this seems to be a recurring problem, let's just add a little
helper function and print the error codes returned by library calls.
