[compiler] Reuse parse info when ensuring deopt support.

src/compiler.cc

 // 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.
 
 #include "src/compiler.h"
 
 #include <algorithm>
 
 #include "src/ast/ast-numbering.h"
 #include "src/ast/prettyprinter.h"
@@ skipping 1180 matching lines @@
   return true;
 }
 
 // TODO(turbofan): In the future, unoptimized code with deopt support could
 // be generated lazily once deopt is triggered.
 bool Compiler::EnsureDeoptimizationSupport(CompilationInfo* info) {
   DCHECK_NOT_NULL(info->literal());
   DCHECK_NOT_NULL(info->scope());
   Handle<SharedFunctionInfo> shared = info->shared_info();
   if (!shared->has_deoptimization_support()) {
-    // TODO(titzer): just reuse the ParseInfo for the unoptimized compile.
-    CompilationInfoWithZone unoptimized(info->closure());
-    // Note that we use the same AST that we will use for generating the
-    // optimized code.
-    ParseInfo* parse_info = unoptimized.parse_info();
-    parse_info->set_literal(info->literal());
-    parse_info->set_scope(info->scope());
-    parse_info->set_context(info->context());
+    Zone zone(info->isolate()->allocator());
+    CompilationInfo unoptimized(info->parse_info(), info->closure());
     unoptimized.EnableDeoptimizationSupport();
     // If the current code has reloc info for serialization, also include
     // reloc info for serialization for the new code, so that deopt support
     // can be added without losing IC state.
     if (shared->code()->kind() == Code::FUNCTION &&
         shared->code()->has_reloc_info_for_serialization()) {
       unoptimized.PrepareForSerializing();
     }
     EnsureFeedbackVector(&unoptimized);
     if (!FullCodeGenerator::MakeCode(&unoptimized)) return false;
@@ skipping 467 matching lines @@
     MaybeHandle<Code> code;
     if (cached.code != nullptr) code = handle(cached.code);
     Handle<Context> native_context(function->context()->native_context());
     SharedFunctionInfo::AddToOptimizedCodeMap(shared, native_context, code,
                                               literals, BailoutId::None());
   }
 }
 
 }  // namespace internal
 }  // namespace v8