[turbofan] Better and more sane support for tail calls

test/mjsunit/call-runtime-tail.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 --nostress-opt --turbo
-// Flags: --nonative-context-specialization
-
-var p0 = new Object();
-var p1 = new Object();
-var p2 = new Object();
-
-// Ensure 1 parameter passed straight-through is handled correctly
-var count1 = 100000;
-tailee1 = function() {
-  "use strict";
-  if (count1-- == 0) {
-    return this;
-  }
-  return %_Call(tailee1, this);
-};
-
-%OptimizeFunctionOnNextCall(tailee1);
-assertEquals(p0, tailee1.call(p0));
-
-// Ensure 2 parameters passed straight-through trigger a tail call are handled
-// correctly and don't cause a stack overflow.
-var count2 = 100000;
-tailee2 = function(px) {
-  "use strict";
-  assertEquals(p2, px);
-  assertEquals(p1, this);
-  count2 = ((count2 | 0) - 1) | 0;
-  if ((count2 | 0) === 0) {
-    return this;
-  }
-  return %_Call(tailee2, this, px);
-};
-
-%OptimizeFunctionOnNextCall(tailee2);
-assertEquals(p1, tailee2.call(p1, p2));
-
-// Ensure swapped 2 parameters don't trigger a tail call (parameter swizzling
-// for the tail call isn't supported yet).
-var count3 = 100000;
-tailee3 = function(px) {
-  "use strict";
-  if (count3-- == 0) {
-    return this;
-  }
-  return %_Call(tailee3, px, this);
-};
-
-%OptimizeFunctionOnNextCall(tailee3);
-assertThrows(function() { tailee3.call(p1, p2); });
-
-// Ensure too many parameters defeats the tail call optimization (currently
-// unsupported).
-var count4 = 1000000;
-tailee4 = function(px) {
-  "use strict";
-  if (count4-- == 0) {
-    return this;
-  }
-  return %_Call(tailee4, this, px, undefined);
-};
-
-%OptimizeFunctionOnNextCall(tailee4);
-assertThrows(function() { tailee4.call(p1, p2); });
-
-// Ensure too few parameters defeats the tail call optimization (currently
-// unsupported).
-var count5 = 1000000;
-tailee5 = function(px) {
-  "use strict";
-  if (count5-- == 0) {
-    return this;
-  }
-  return %_Call(tailee5, this);
-};
-
-%OptimizeFunctionOnNextCall(tailee5);
-assertThrows(function() { tailee5.call(p1, p2); });