Remove FLAG_opt_safe_uint32_operations.

src/arm64/lithium-arm64.cc

 // Copyright 2013 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 <sstream>
 
 #include "src/v8.h"
 
 #include "src/arm64/lithium-codegen-arm64.h"
 #include "src/hydrogen-osr.h"
@@ skipping 2218 matching lines @@
       ? UseRegister(instr->left())
       : UseRegisterAtStart(instr->left());
   LOperand* right = UseRegisterOrConstantAtStart(instr->right());
 
   // The only shift that can deoptimize is `left >>> 0`, where left is negative.
   // In these cases, the result is a uint32 that is too large for an int32.
   bool right_can_be_zero = !instr->right()->IsConstant() ||
                            (JSShiftAmountFromHConstant(instr->right()) == 0);
   bool can_deopt = false;
   if ((op == Token::SHR) && right_can_be_zero) {
-    if (FLAG_opt_safe_uint32_operations) {
-      can_deopt = !instr->CheckFlag(HInstruction::kUint32);
-    } else {
-      can_deopt = !instr->CheckUsesForFlag(HValue::kTruncatingToInt32);
-    }
+    can_deopt = !instr->CheckFlag(HInstruction::kUint32);
   }
 
   LInstruction* result;
   if (instr->representation().IsInteger32()) {
     result = DefineAsRegister(new (zone()) LShiftI(op, left, right, can_deopt));
   } else {
     DCHECK(instr->representation().IsSmi());
     result = DefineAsRegister(new (zone()) LShiftS(op, left, right, can_deopt));
   }
 
@@ skipping 494 matching lines @@
     HAllocateBlockContext* instr) {
   LOperand* context = UseFixed(instr->context(), cp);
   LOperand* function = UseRegisterAtStart(instr->function());
   LAllocateBlockContext* result =
       new(zone()) LAllocateBlockContext(context, function);
   return MarkAsCall(DefineFixed(result, cp), instr);
 }
 
 
 } }  // namespace v8::internal