Throw TypeError in Instant.round if options is und

Make the Instant.prototype.round() throw also TypeError instead of RangeError if options is undefined.

Author: FrankYFTang

spec/instant.html

@@ -304,6 +304,8 @@ <h1>Temporal.Instant.prototype.round ( _options_ )</h1>
       <emu-alg>
         1. Let _instant_ be the *this* value.
         1. Perform ? RequireInternalSlot(_instant_, [[InitializedTemporalInstant]]).
+        1. If _options_ is *undefined*, then
+          1. Throw a *TypeError* exception.
         1. Set _options_ to ? GetOptionsObject(_options_).
         1. Let _smallestUnit_ be ? ToSmallestTemporalUnit(_options_, « *"year"*, *"month"*, *"week"*, *"day"* », *undefined*).
         1. If _smallestUnit_ is *undefined*, throw a *RangeError* exception.