[turbofan] Turn common Guard operator into simplified TypeGuard.

src/compiler/simplified-operator.h

Index: src/compiler/simplified-operator.h
diff --git a/src/compiler/simplified-operator.h b/src/compiler/simplified-operator.h
index f0b343bc882ff1a963029edc20726219b5ca394e..20d8a39d1c5aeebe85d52c7e067a2b802e976605 100644
--- a/src/compiler/simplified-operator.h
+++ b/src/compiler/simplified-operator.h
@@ -102,6 +102,7 @@ std::ostream& operator<<(std::ostream&, ElementAccess const&);
 
 ElementAccess const& ElementAccessOf(const Operator* op) WARN_UNUSED_RESULT;
 
+Type* TypeOf(const Operator* op) WARN_UNUSED_RESULT;
 
 // Interface for building simplified operators, which represent the
 // medium-level operations of V8, including adding numbers, allocating objects,
@@ -182,6 +183,8 @@ class SimplifiedOperatorBuilder final : public ZoneObject {
   const Operator* ObjectIsString();
   const Operator* ObjectIsUndetectable();
 
+  const Operator* TypeGuard(Type* type);
+
   const Operator* Allocate(PretenureFlag pretenure = NOT_TENURED);
 
   const Operator* LoadField(FieldAccess const&);