[turbofan] Simply context specialization and fix for OSR.

test/cctest/compiler/test-js-context-specialization.cc

 // Copyright 2014 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.
 
 #include "src/compiler/js-context-specialization.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/source-position.h"
 #include "test/cctest/cctest.h"
@@ skipping 42 matching lines @@
   Handle<Context> subcontext2 = t.factory()->NewNativeContext();
   subcontext2->set_previous(*subcontext1);
   subcontext1->set_previous(*native);
   Handle<Object> expected = t.factory()->InternalizeUtf8String("gboy!");
   const int slot = Context::GLOBAL_OBJECT_INDEX;
   native->set(slot, *expected);
 
   Node* const_context = t.jsgraph()->Constant(native);
   Node* deep_const_context = t.jsgraph()->Constant(subcontext2);
   Node* param_context = t.NewNode(t.common()->Parameter(0), start);
-  JSContextSpecializer spec(Handle<Context>(), t.jsgraph(), const_context);
+  JSContextSpecializer spec(t.jsgraph());
 
   {
     // Mutable slot, constant context, depth = 0 => do nothing.
     Node* load = t.NewNode(t.javascript()->LoadContext(0, 0, false),
                            const_context, const_context, start);
     Reduction r = spec.ReduceJSLoadContext(load);
     CHECK(!r.Changed());
   }
 
   {
@@ skipping 51 matching lines @@
   Handle<Context> subcontext2 = t.factory()->NewNativeContext();
   subcontext2->set_previous(*subcontext1);
   subcontext1->set_previous(*native);
   Handle<Object> expected = t.factory()->InternalizeUtf8String("gboy!");
   const int slot = Context::GLOBAL_OBJECT_INDEX;
   native->set(slot, *expected);
 
   Node* const_context = t.jsgraph()->Constant(native);
   Node* deep_const_context = t.jsgraph()->Constant(subcontext2);
   Node* param_context = t.NewNode(t.common()->Parameter(0), start);
-  JSContextSpecializer spec(Handle<Context>(), t.jsgraph(), const_context);
+  JSContextSpecializer spec(t.jsgraph());
 
   {
     // Mutable slot, constant context, depth = 0 => do nothing.
     Node* load = t.NewNode(t.javascript()->StoreContext(0, 0), const_context,
                            const_context, start);
     Reduction r = spec.ReduceJSStoreContext(load);
     CHECK(!r.Changed());
   }
 
   {
@@ skipping 44 matching lines @@
   t.graph()->SetStart(start);
 
   // Make a context and initialize it a bit for this test.
   Handle<Context> native = t.factory()->NewNativeContext();
   Handle<Object> expected = t.factory()->InternalizeUtf8String("gboy!");
   const int slot = Context::GLOBAL_OBJECT_INDEX;
   native->set(slot, *expected);
 
   Node* const_context = t.jsgraph()->Constant(native);
   Node* param_context = t.NewNode(t.common()->Parameter(0), start);
-  JSContextSpecializer spec(native, t.jsgraph(), const_context);
+  JSContextSpecializer spec(t.jsgraph());
 
   {
     // Check that specialization replaces values and forwards effects
     // correctly, and folds values from constant and non-constant contexts
     Node* effect_in = start;
     Node* load = t.NewNode(t.javascript()->LoadContext(0, slot, true),
                            const_context, const_context, effect_in);
 
 
     Node* value_use = t.NewNode(t.simplified()->ChangeTaggedToInt32(), load);
@@ skipping 83 matching lines @@
   {
     FunctionTester T(
         "(function() { if (false) { var x = 1; } function inc(a)"
         " { return a + x; } return inc; })()");  // x is undefined!
 
     CHECK(T.Call(T.Val(0.0), T.Val(0.0)).ToHandleChecked()->IsNaN());
     CHECK(T.Call(T.Val(2.0), T.Val(0.0)).ToHandleChecked()->IsNaN());
     CHECK(T.Call(T.Val(-2.1), T.Val(0.0)).ToHandleChecked()->IsNaN());
   }
 }