Revert of [Atomics] code stubs for atomic operations

src/compiler/code-stub-assembler.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/compiler/code-stub-assembler.h"
 
 #include <ostream>
 
 #include "src/code-factory.h"
 #include "src/compiler/graph.h"
@@ skipping 1258 matching lines @@
         MachineRepresentation::kWord16, result,
         IntPtrConstant(SeqTwoByteString::kHeaderSize - kHeapObjectTag), code);
     var_result.Bind(result);
     Goto(&if_done);
   }
 
   Bind(&if_done);
   return var_result.value();
 }
 
-Node* CodeStubAssembler::TruncateFloat64ToInt32(Node* value) {
-  return raw_assembler_->TruncateFloat64ToInt32(TruncationMode::kJavaScript,
-                                                value);
-}
-
 void CodeStubAssembler::BranchIf(Node* condition, Label* if_true,
                                  Label* if_false) {
   Label if_condition_is_true(this), if_condition_is_false(this);
   Branch(condition, &if_condition_is_true, &if_condition_is_false);
   Bind(&if_condition_is_true);
   Goto(if_true);
   Bind(&if_condition_is_false);
   Goto(if_false);
 }
 
@@ skipping 425 matching lines @@
       }
     }
   }
 
   bound_ = true;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8