[csa] Migrate String.prototype.concat to TurboFan builtin.

src/debug/debug-evaluate.cc

 // 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.
 
 #include "src/debug/debug-evaluate.h"
 
 #include "src/accessors.h"
 #include "src/compiler.h"
 #include "src/contexts.h"
 #include "src/debug/debug-frames.h"
@@ skipping 506 matching lines @@
     case Builtins::kNumberPrototypeToFixed:
     case Builtins::kNumberPrototypeToPrecision:
     case Builtins::kNumberPrototypeToString:
     case Builtins::kNumberPrototypeValueOf:
     // String builtins. Strings are immutable.
     case Builtins::kStringFromCharCode:
     case Builtins::kStringFromCodePoint:
     case Builtins::kStringConstructor:
     case Builtins::kStringPrototypeCharAt:
     case Builtins::kStringPrototypeCharCodeAt:
+    case Builtins::kStringPrototypeConcat:
     case Builtins::kStringPrototypeEndsWith:
     case Builtins::kStringPrototypeIncludes:
     case Builtins::kStringPrototypeIndexOf:
     case Builtins::kStringPrototypeLastIndexOf:
     case Builtins::kStringPrototypeStartsWith:
     case Builtins::kStringPrototypeSubstr:
     case Builtins::kStringPrototypeSubstring:
     case Builtins::kStringPrototypeToString:
     case Builtins::kStringPrototypeToLowerCase:
     case Builtins::kStringPrototypeToUpperCase:
@@ skipping 97 matching lines @@
 
   if (FLAG_trace_side_effect_free_debug_evaluate) {
     PrintF("[debug-evaluate] API Callback at %p may cause side effect.\n",
            reinterpret_cast<void*>(function_addr));
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8