[turbofan] Use heavy-handed graph duplication to do loop peeling for OSR.

test/mjsunit/compiler/osr-maze1.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 --use-osr --turbo-deoptimization
+
+function bar(goal) {
+  var count = 0;
+  var sum = 11;
+  var i = 35;
+  while (i-- > 33) {
+    if (count++ == goal) %OptimizeOsr();
+    sum = sum + i;
+  }
+  while (i-- > 31) {
+    if (count++ == goal) %OptimizeOsr();
+    j = 9;
+    while (j-- > 7) {
+      if (count++ == goal) %OptimizeOsr();
+      sum = sum + j * 3;
+    }
+    while (j-- > 5) {
+      if (count++ == goal) %OptimizeOsr();
+      sum = sum + j * 5;
+    }
+  }
+  while (i-- > 29) {
+    if (count++ == goal) %OptimizeOsr();
+    while (j-- > 3) {
+      var k = 10;
+      if (count++ == goal) %OptimizeOsr();
+      while (k-- > 8) {
+        if (count++ == goal) %OptimizeOsr();
+        sum = sum + k * 11;
+      }
+    }
+    while (j-- > 1) {
+      if (count++ == goal) %OptimizeOsr();
+      while (k-- > 6) {
+        if (count++ == goal) %OptimizeOsr();
+        sum = sum + j * 13;
+      }
+    }
+  }
+  print(count);
+  return sum;
+}
+
+for (var i = 0; i < 13; i++) {
+  %DeoptimizeFunction(bar);
+  assertEquals(348, bar(i));
+}