[csa] Replace remaining old-style GetProperty calls

src/builtins/builtins-string.cc

 // 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.
 
 #include "src/builtins/builtins-regexp.h"
 #include "src/builtins/builtins-utils.h"
 #include "src/builtins/builtins.h"
 #include "src/code-factory.h"
 #include "src/code-stub-assembler.h"
 #include "src/conversions.h"
@@ skipping 1208 matching lines @@
     Bind(&stub_call);
     Return(regexp_call());
 
     Bind(&slow_lookup);
   }
 
   GotoIf(IsNullOrUndefined(object), &out);
 
   // Fall back to a slow lookup of {object[symbol]}.
 
-  Callable getproperty_callable = CodeFactory::GetProperty(isolate());
-  Node* const key = HeapConstant(symbol);
-  Node* const maybe_func = CallStub(getproperty_callable, context, object, key);
-
+  Node* const maybe_func = GetProperty(context, object, symbol);
   GotoIf(IsUndefined(maybe_func), &out);
 
   // Attempt to call the function.
 
   Node* const result = generic_call(maybe_func);
   Return(result);
 
   Bind(&out);
 }
 
@@ skipping 916 matching lines @@
 
 BUILTIN(StringPrototypeToUpperCase) {
   HandleScope scope(isolate);
   TO_THIS_STRING(string, "String.prototype.toUpperCase");
   return ConvertCase(string, isolate,
                      isolate->runtime_state()->to_upper_mapping());
 }
 
 }  // namespace internal
 }  // namespace v8