Tweak the TurboFan pipeline for stub compilation.

src/compiler.h

 // Copyright 2012 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_H_
 #define V8_COMPILER_H_
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/bailout-reason.h"
@@ skipping 145 matching lines @@
   Zone* zone() { return zone_; }
   bool is_osr() const { return !osr_ast_id_.IsNone(); }
   Handle<Code> code() const { return code_; }
   CodeStub* code_stub() const { return code_stub_; }
   BailoutId osr_ast_id() const { return osr_ast_id_; }
   Handle<Code> unoptimized_code() const { return unoptimized_code_; }
   int opt_count() const { return opt_count_; }
   int num_parameters() const;
   int num_heap_slots() const;
   Code::Flags flags() const;
+  bool has_scope() const { return scope() != nullptr; }
 
   void set_parameter_count(int parameter_count) {
     DCHECK(IsStub());
     parameter_count_ = parameter_count;
   }
 
   bool is_tracking_positions() const { return track_positions_; }
 
   bool is_calling() const {
     return GetFlag(kDeferredCalling) || GetFlag(kNonDeferredCalling);
@@ skipping 87 matching lines @@
   bool IsOptimizable() const { return mode_ == BASE; }
   bool IsStub() const { return mode_ == STUB; }
   void SetOptimizing(BailoutId osr_ast_id, Handle<Code> unoptimized) {
     DCHECK(!shared_info().is_null());
     SetMode(OPTIMIZE);
     osr_ast_id_ = osr_ast_id;
     unoptimized_code_ = unoptimized;
     optimization_id_ = isolate()->NextOptimizationId();
   }
 
+  void SetStub(CodeStub* code_stub) {
+    SetMode(STUB);
+    code_stub_ = code_stub;
+  }
+
   // Deoptimization support.
   bool HasDeoptimizationSupport() const {
     return GetFlag(kDeoptimizationSupport);
   }
   void EnableDeoptimizationSupport() {
     DCHECK(IsOptimizable());
     SetFlag(kDeoptimizationSupport);
   }
 
   // Determines whether or not to insert a self-optimization header.
@@ skipping 417 matching lines @@
   Zone zone_;
   size_t info_zone_start_allocation_size_;
   base::ElapsedTimer timer_;
 
   DISALLOW_COPY_AND_ASSIGN(CompilationPhase);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_COMPILER_H_