[turbofan] Add new StringFromCharCode simplified operator.

src/compiler/pipeline.cc

 // Copyright 2014 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/pipeline.h"
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/base/adapters.h"
@@ skipping 1402 matching lines @@
       Run<EscapeAnalysisPhase>();
       RunPrintAndVerify("Escape Analysed");
     }
 
     // Select representations.
     Run<RepresentationSelectionPhase>();
     RunPrintAndVerify("Representations selected");
 
     // Run early optimization pass.
     Run<EarlyOptimizationPhase>();
-    RunPrintAndVerify("Early optimized");
+    RunPrintAndVerify("Early optimized", true);
   }
 
 #ifdef DEBUG
   // From now on it is invalid to look at types on the nodes, because:
   //
   //  (a) The remaining passes (might) run concurrent to the main thread and
   //      therefore must not access the Heap or the Isolate in an uncontrolled
   //      way (as done by the type system), and
   //  (b) the types on the nodes might not make sense after representation
   //      selection due to the way we handle truncations; if we'd want to look
@@ skipping 365 matching lines @@
   data->DeleteRegisterAllocationZone();
 }
 
 CompilationInfo* PipelineImpl::info() const { return data_->info(); }
 
 Isolate* PipelineImpl::isolate() const { return info()->isolate(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8