Normative: Don't fall back to default locale in Locale.p.getCollations() - #1072

This commit provides additional coverage for the CollationsOfLocale AO,
in preparation for the normative change in
tc39/ecma402#1072.

LLM disclosure: I used a bot to draft these tests, and hand-edited them
until I was satisfied. default-locale-fallback.js is heavily commented,
but I did actually remove all the LLM comment spew; what's left are my
own comments.

With normative PR tc39/ecma402#1072, the
unmatched locales (e.g. qfz, qga-DE, etc.) are hardcoded to return
the root collations ["emoji", "eor"] from getCollations(). The und
locales are no longer hardcoded, but it's a safe assumption that they
will also return the root collations. Combine the two tests that dealt
with und and unmatched locales into one.

This commit provides additional coverage for the CollationsOfLocale AO,
in preparation for the normative change in
tc39/ecma402#1072.

LLM disclosure: I used a bot to draft these tests, and hand-edited them
until I was satisfied. default-locale-fallback.js is heavily commented,
but I did actually remove all the LLM comment spew; what's left are my
own comments.

With normative PR tc39/ecma402#1072, the
unmatched locales (e.g. qfz, qga-DE, etc.) are hardcoded to return
the root collations ["emoji", "eor"] from getCollations(). The und
locales are no longer hardcoded, but it's a safe assumption that they
will also return the root collations. Combine the two tests that dealt
with und and unmatched locales into one.

This commit provides additional coverage for the CollationsOfLocale AO,
in preparation for the normative change in
tc39/ecma402#1072.

LLM disclosure: I used a bot to draft these tests, and hand-edited them
until I was satisfied. default-locale-fallback.js is heavily commented,
but I did actually remove all the LLM comment spew; what's left are my
own comments.

With normative PR tc39/ecma402#1072, the
unmatched locales (e.g. qfz, qga-DE, etc.) are hardcoded to return
the root collations ["emoji", "eor"] from getCollations(). The und
locales are no longer hardcoded, but it's a safe assumption that they
will also return the root collations. Combine the two tests that dealt
with und and unmatched locales into one.

This commit provides additional coverage for the CollationsOfLocale AO,
in preparation for the normative change in
tc39/ecma402#1072.

LLM disclosure: I used a bot to draft these tests, and hand-edited them
until I was satisfied. default-locale-fallback.js is heavily commented,
but I did actually remove all the LLM comment spew; what's left are my
own comments.

With normative PR tc39/ecma402#1072, the
unmatched locales (e.g. qfz, qga-DE, etc.) are hardcoded to return
the root collations ["emoji", "eor"] from getCollations(). The und
locales are no longer hardcoded, but it's a safe assumption that they
will also return the root collations. Combine the two tests that dealt
with und and unmatched locales into one.

This commit provides additional coverage for the CollationsOfLocale AO,
in preparation for the normative change in
tc39/ecma402#1072.

LLM disclosure: I used a bot to draft these tests, and hand-edited them
until I was satisfied. default-locale-fallback.js is heavily commented,
but I did actually remove all the LLM comment spew; what's left are my
own comments.

With normative PR tc39/ecma402#1072, the
unmatched locales (e.g. qfz, qga-DE, etc.) are hardcoded to return
the root collations ["emoji", "eor"] from getCollations(). The und
locales are no longer hardcoded, but it's a safe assumption that they
will also return the root collations. Combine the two tests that dealt
with und and unmatched locales into one.

Bumps the pinned suite to defaaf1571cd13b183e3f505c6a06e8db316e593. Three
things came in with it, and all three needed engine work to stay green.

Iterator.prototype.join (https://github.com/tc39/proposal-iterator-join) is the
new feature, with 18 tests. Joining is the easy half; which failures close the
receiver is the part worth reading the tests for. Coercing the separator closes
it, and so does coercing a value the iterator produced. An abrupt `next` lookup,
a throwing `next()`, and a protocol violation (a step result that is not an
object) all propagate without closing, because IteratorStepValue marks the
record done first. Exhaustion does not close either. The separator is coerced
*before* `next` is read, so a receiver whose `next` getter throws never gets
that far, and `next` is read exactly once however many steps follow. Nullish
values format as the empty string, as they do in Array.prototype.join.

Intl.Locale.prototype.getCollations picked up a normative change
(tc39/ecma402#1072): a tag matching no available
Collator locale no longer falls back to the default locale — it reports the
hardcoded root collations « "emoji", "eor" » — and the result is now sorted in
lexicographic code unit order. Jint reported a single-element ["default"] for
every locale, and "default" is Jint's internal placeholder for "no collation was
requested", not an identifier a locale can report at all. It now reports the
root collations plus whatever the language adds, sorted; an explicitly requested
collation, however it was requested, is still the whole answer. The data comes
from the table CollatorConstructor already kept, so nothing new was invented:
"de" reports ["emoji","eor","phonebk"], "zh" its seven, "tr" and "und" and any
private-use tag the bare root pair.

import-defer grew IsModuleSCCEvaluated, and Jint needed it. A module that
finished its own body is only really done once the strongly connected component
it belongs to is: a member of an async cycle reaches EVALUATED as soon as its
body returns, while the cycle root sits in EVALUATING-ASYNC awaiting a top-level
await. Reading the member's own status is what
GatherAsynchronousTransitiveDependencies and ReadyForSyncExecution were doing,
so a deferred subgraph reaching into such a cycle looked free of async
dependencies — and the deferring module ran its body, and took its deferred
namespace, before the cycle had finished. The new test walks exactly that graph.
ReadyForSyncExecution refuses an EVALUATED-but-not-SCC-evaluated module rather
than asserting on it: the spec asserts LINKED at that point, having convinced
itself the state is unreachable, and refusing is both the conservative answer
and the one EvaluateSync already turns into the spec's TypeError.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>