[turbofan] Simply context specialization and fix for OSR.

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

Index: test/cctest/compiler/test-js-context-specialization.cc
diff --git a/test/cctest/compiler/test-js-context-specialization.cc b/test/cctest/compiler/test-js-context-specialization.cc
index f4500c71844b561fd3f920d6d65a900e2fdc3840..e2cb8e6ac94ec8b8b3520e8eb0f1c980fbb3bcb5 100644
--- a/test/cctest/compiler/test-js-context-specialization.cc
+++ b/test/cctest/compiler/test-js-context-specialization.cc
@@ -60,7 +60,7 @@ TEST(ReduceJSLoadContext) {
   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.
@@ -132,7 +132,7 @@ TEST(ReduceJSStoreContext) {
   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.
@@ -197,7 +197,7 @@ TEST(SpecializeToContext) {
 
   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