Add Smi::Zero and replace all Smi::FromInt(0) calls

src/s390/macro-assembler-s390.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 <assert.h>  // For assert
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_S390
 
 #include "src/base/bits.h"
@@ skipping 3153 matching lines @@
   b(&index_tag_ok);
   bind(&index_tag_bad);
   Abort(kIndexIsTooLarge);
   bind(&index_tag_ok);
 #endif
 
   LoadP(ip, FieldMemOperand(string, String::kLengthOffset));
   CmpP(index, ip);
   Check(lt, kIndexIsTooLarge);
 
-  DCHECK(Smi::FromInt(0) == 0);
+  DCHECK(Smi::kZero == 0);
   CmpP(index, Operand::Zero());
   Check(ge, kIndexIsNegative);
 
   SmiUntag(index, index);
 }
 
 void MacroAssembler::PrepareCallCFunction(int num_reg_arguments,
                                           int num_double_arguments,
                                           Register scratch) {
   int frame_alignment = ActivationFrameAlignment();
@@ skipping 304 matching lines @@
   beq(call_runtime);
 
   LoadRoot(null_value, Heap::kNullValueRootIndex);
   b(&start, Label::kNear);
 
   bind(&next);
   LoadP(r3, FieldMemOperand(r4, HeapObject::kMapOffset));
 
   // For all objects but the receiver, check that the cache is empty.
   EnumLength(r5, r3);
-  CmpSmiLiteral(r5, Smi::FromInt(0), r0);
+  CmpSmiLiteral(r5, Smi::kZero, r0);
   bne(call_runtime);
 
   bind(&start);
 
   // Check that there are no elements. Register r4 contains the current JS
   // object we've reached through the prototype chain.
   Label no_elements;
   LoadP(r4, FieldMemOperand(r4, JSObject::kElementsOffset));
   CmpP(r4, empty_fixed_array_value);
   beq(&no_elements, Label::kNear);
@@ skipping 2023 matching lines @@
   }
   if (mag.shift > 0) ShiftRightArith(result, result, Operand(mag.shift));
   ExtractBit(r0, dividend, 31);
   AddP(result, r0);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_S390