[builtins] Introduce proper Float64Tan operator.

test/mjsunit/asm/construct-double.js

-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --allow-natives-syntax
-
-var stdlib = this;
-var foreign = {};
-var heap = new ArrayBuffer(64 * 1024);
-
-
-var m = (function(stdlib, foreign, heap) {
-  "use asm";
-  function cd1(i, j) {
-    i = i|0;
-    j = j|0;
-    return +%_ConstructDouble(i, j);
-  }
-  function cd2(i) {
-    i = i|0;
-    return +%_ConstructDouble(0, i);
-  }
-  return { cd1: cd1, cd2: cd2 };
-})(stdlib, foreign, heap);
-
-assertEquals(0.0, m.cd1(0, 0));
-assertEquals(%ConstructDouble(0, 1), m.cd2(1));
-for (var i = -2147483648; i < 2147483648; i += 3999773) {
-  assertEquals(%ConstructDouble(0, i), m.cd2(i));
-  for (var j = -2147483648; j < 2147483648; j += 3999773) {
-    assertEquals(%ConstructDouble(i, j), m.cd1(i, j));
-  }
-}