This is a normative change in the Intl.NumberFormat V3 spec. See:
https://github.com/tc39/proposal-intl-numberformat-v3/commit/08f599b
Note that this didn't seem to actually affect our implementation. The
Unicode spec states:
https://www.unicode.org/reports/tr35/tr35-53/tr35-numbers.html#Plural_Ranges
"If there is no value for a <start,end> pair, the default result is end"
Therefore, our implementation did not have the behavior noted by the
issue this normative change addressed:
const pr = new Intl.PluralRules("en-US");
pr.selectRange(1, 1); // Is "other", should be "one"
Our implementation already returned "one" here because there is no such
<start=one, end=one> value in the CLDR for en-US. Thus, we already
returned the end value of "one".
e74e8381d5