[turbofan] Introduce CheckTaggedSigned and CheckTaggedPointer operators.

src/compiler/js-create-lowering.cc

 // Copyright 2016 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-create-lowering.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
@@ skipping 19 matching lines @@
 class AllocationBuilder final {
  public:
   AllocationBuilder(JSGraph* jsgraph, Node* effect, Node* control)
       : jsgraph_(jsgraph),
         allocation_(nullptr),
         effect_(effect),
         control_(control) {}
 
   // Primitive allocation of static size.
   void Allocate(int size, PretenureFlag pretenure = NOT_TENURED) {
-    effect_ = graph()->NewNode(common()->BeginRegion(), effect_);
+    effect_ = graph()->NewNode(
+        common()->BeginRegion(RegionObservability::kNotObservable), effect_);
     allocation_ =
         graph()->NewNode(simplified()->Allocate(pretenure),
                          jsgraph()->Constant(size), effect_, control_);
     effect_ = allocation_;
   }
 
   // Primitive store into a field.
   void Store(const FieldAccess& access, Node* value) {
     effect_ = graph()->NewNode(simplified()->StoreField(access), allocation_,
                                value, effect_, control_);
@@ skipping 890 matching lines @@
                                        isolate());
       if (boilerplate_value->IsJSObject()) {
         Handle<JSObject> boilerplate_object =
             Handle<JSObject>::cast(boilerplate_value);
         Handle<AllocationSite> current_site = site_context->EnterNewScope();
         value = effect = AllocateFastLiteral(effect, control,
                                              boilerplate_object, site_context);
         site_context->ExitScope(current_site, boilerplate_object);
       } else if (property_details.representation().IsDouble()) {
         // Allocate a mutable HeapNumber box and store the value into it.
-        effect = graph()->NewNode(common()->BeginRegion(), effect);
+        effect = graph()->NewNode(
+            common()->BeginRegion(RegionObservability::kNotObservable), effect);
         value = effect = graph()->NewNode(
             simplified()->Allocate(NOT_TENURED),
             jsgraph()->Constant(HeapNumber::kSize), effect, control);
         effect = graph()->NewNode(
             simplified()->StoreField(AccessBuilder::ForMap()), value,
             jsgraph()->HeapConstant(factory()->mutable_heap_number_map()),
             effect, control);
         effect = graph()->NewNode(
             simplified()->StoreField(AccessBuilder::ForHeapNumberValue()),
             value, jsgraph()->Constant(
@@ skipping 163 matching lines @@
   return jsgraph()->simplified();
 }
 
 MachineOperatorBuilder* JSCreateLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8