Reland: [Compiler] Enable handles created during parsing and scope analysis to be deferred.

src/compilation-info.h

 // 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.
 
 #ifndef V8_COMPILATION_INFO_H_
 #define V8_COMPILATION_INFO_H_
 
 #include <memory>
 
 #include "src/compilation-dependencies.h"
@@ skipping 214 matching lines @@
     DCHECK_EQ(BASE, mode_);
     SetFlag(kDeoptimizationSupport);
   }
   bool ShouldEnsureSpaceForLazyDeopt() { return !IsStub(); }
 
   bool ExpectsJSReceiverAsReceiver();
 
   // Determines whether or not to insert a self-optimization header.
   bool ShouldSelfOptimize();
 
-  void set_deferred_handles(DeferredHandles* deferred_handles) {
-    DCHECK(deferred_handles_ == NULL);
-    deferred_handles_ = deferred_handles;
+  void set_deferred_handles(std::shared_ptr<DeferredHandles> deferred_handles);
+  void set_deferred_handles(DeferredHandles* deferred_handles);
+  std::shared_ptr<DeferredHandles> deferred_handles() {
+    return deferred_handles_;
   }
 
   void ReopenHandlesInNewHandleScope();
 
   void AbortOptimization(BailoutReason reason) {
     DCHECK(reason != kNoReason);
     if (bailout_reason_ == kNoReason) bailout_reason_ = reason;
     SetFlag(kDisableFutureOptimization);
   }
 
@@ skipping 109 matching lines @@
 
   // Holds the bytecode array generated by the interpreter.
   // TODO(rmcilroy/mstarzinger): Temporary work-around until compiler.cc is
   // refactored to avoid us needing to carry the BytcodeArray around.
   Handle<BytecodeArray> bytecode_array_;
 
   // The zone from which the compilation pipeline working on this
   // CompilationInfo allocates.
   Zone* zone_;
 
-  DeferredHandles* deferred_handles_;
+  std::shared_ptr<DeferredHandles> deferred_handles_;
 
   // Dependencies for this compilation, e.g. stable maps.
   CompilationDependencies dependencies_;
 
   BailoutReason bailout_reason_;
 
   int prologue_offset_;
 
   InlinedFunctionList inlined_functions_;
 
   // Number of parameters used for compilation of stubs that require arguments.
   int parameter_count_;
 
   int optimization_id_;
 
   int osr_expr_stack_height_;
 
   // The current OSR frame for specialization or {nullptr}.
   JavaScriptFrame* osr_frame_ = nullptr;
 
   Vector<const char> debug_name_;
 
   DISALLOW_COPY_AND_ASSIGN(CompilationInfo);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILATION_INFO_H_