[compiler] Introduce StringEqualStub and StringNotEqualStub.

src/compiler/code-stub-assembler.h

 // 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.
 
 #ifndef V8_COMPILER_CODE_STUB_ASSEMBLER_H_
 #define V8_COMPILER_CODE_STUB_ASSEMBLER_H_
 
 #include <map>
 
 // Clients of this interface shouldn't depend on lots of compiler internals.
 // Do not include anything from src/compiler here!
 #include "src/allocation.h"
 #include "src/builtins.h"
 #include "src/heap/heap.h"
 #include "src/machine-type.h"
 #include "src/runtime/runtime.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 
+class Callable;
 class CallInterfaceDescriptor;
 class Isolate;
 class Factory;
 class Zone;
 
 namespace compiler {
 
 class CallDescriptor;
 class Graph;
 class Node;
@@ skipping 176 matching lines @@
   Node* CallStub(const CallInterfaceDescriptor& descriptor, Node* target,
                  Node* context, Node* arg1, Node* arg2, Node* arg3,
                  size_t result_size = 1);
   Node* CallStub(const CallInterfaceDescriptor& descriptor, Node* target,
                  Node* context, Node* arg1, Node* arg2, Node* arg3, Node* arg4,
                  size_t result_size = 1);
   Node* CallStub(const CallInterfaceDescriptor& descriptor, Node* target,
                  Node* context, Node* arg1, Node* arg2, Node* arg3, Node* arg4,
                  Node* arg5, size_t result_size = 1);
 
+  Node* TailCallStub(Callable const& callable, Node* context, Node* arg1,
+                     Node* arg2, size_t result_size = 1);
+
   Node* TailCallStub(const CallInterfaceDescriptor& descriptor, Node* target,
                      Node* context, Node* arg1, Node* arg2,
                      size_t result_size = 1);
 
   Node* TailCall(const CallInterfaceDescriptor& descriptor, Node* target,
                  Node** args, size_t result_size = 1);
 
   // ===========================================================================
   // Macros
   // ===========================================================================
@@ skipping 114 matching lines @@
   // Map of variables to the list of value nodes that have been added from each
   // merge path in their order of merging.
   std::map<Variable::Impl*, std::vector<Node*>> variable_merges_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_CODE_STUB_ASSEMBLER_H_