Normative: ToInteger: fix spec bug from tc39#1827 that allows (-1,0) to produce -0

Author: ljharb

spec.html

@@ -4831,7 +4831,9 @@ <h1>ToInteger ( _argument_ )</h1>
         1. Let _number_ be ? ToNumber(_argument_).
         1. If _number_ is *NaN*, *+0*, or *-0*, return *+0*.
         1. If _number_ is *+&infin;*, or *-&infin;*, return _number_.
-        1. Return the Number value that is the same sign as _number_ and whose magnitude is floor(abs(_number_)).
+        1. Let _integer_ be floor(abs(_number_)).
+        1. If ! SameValueZero(_integer_, *+0*), return *+0*.
+        1. Return the Number value that is the same sign as _number_ and whose magnitude is _integer_.
       </emu-alg>
     </emu-clause>