Normative: Fix inconsistency in order of observable operations

Previously, the monthDayFromFields() method of non-ISO calendars behaved
differently from dateFromFields() and yearMonthFromFields(), checking the
overflow option after accessing the fields whereas the other two checked
the overflow option first.

This normative change fixes this inconsistency.

spec/intl.html

@@ -1692,8 +1692,8 @@ <h1>Temporal.Calendar.prototype.monthDayFromFields ( _fields_ [ , _options_ ] )<
             1. If _calendar_.[[Identifier]] is *"iso8601"*, then
               1. Let _result_ be ? ISOMonthDayFromFields(_fields_, _options_).
             1. Else,
-              1. Set _fields_ to ? PrepareTemporalFields(_fields_, « *"day"*, *"era"*, *"eraYear"*, *"month"*, *"monthCode"*, *"year"* », « *"day"* »).
               1. Let _overflow_ be ? ToTemporalOverflow(_options_).
+              1. Set _fields_ to ? PrepareTemporalFields(_fields_, « *"day"*, *"era"*, *"eraYear"*, *"month"*, *"monthCode"*, *"year"* », « *"day"* »).
               1. Let _result_ be ? CalendarDateToISO(_calendar_.[[Identifier]], _fields_, _overflow_).
               1. Set _result_.[[ReferenceISOYear]] to _result_.[[Year]].
             1. Return ? CreateTemporalMonthDay(_result_.[[Month]], _result_.[[Day]], _calendar_, _result_.[[ReferenceISOYear]]).