ARM64: Generate optimized code for Math.floor and Math.round with double outputs.

test/mjsunit/math-floor-part4.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 19 matching lines @@
 var test_id = 0;
 
 function testFloor(expect, input) {
   var test = new Function('n',
                           '"' + (test_id++) + '";return Math.floor(n)');
   assertEquals(expect, test(input));
   assertEquals(expect, test(input));
   assertEquals(expect, test(input));
   %OptimizeFunctionOnNextCall(test);
   assertEquals(expect, test(input));
+
+  var test_double_output = new Function(
+      'n',
+      '"' + (test_id++) + '";return Math.floor(n) + -0.0');
+  assertEquals(expect, test_double_output(input));
+  assertEquals(expect, test_double_output(input));
+  assertEquals(expect, test_double_output(input));
+  %OptimizeFunctionOnNextCall(test_double_output);
+  assertEquals(expect, test_double_output(input));
 }
 
 function zero() {
   var x = 0.5;
   return (function() { return x - 0.5; })();
 }
 
 function test() {
   testFloor(0, 0);
   testFloor(0, zero());
@@ skipping 17 matching lines @@
   while (--i > 0) {
     ret += Math.floor(n);
   }
   return ret;
 }
 assertEquals(-0, floorsum(1, -0));
 %OptimizeFunctionOnNextCall(floorsum);
 // The optimized function will deopt.  Run it with enough iterations to try
 // to optimize via OSR (triggering the bug).
 assertEquals(-0, floorsum(100000, -0));