Remove FLAG_opt_safe_uint32_operations.

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index c9462b4f8886310c298647e9fe7642f89e57410d..46897a3726c398786950fc78d20efe393ab1e30a 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -699,11 +699,7 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
     // Shift operations can only deoptimize if we do a logical shift
     // by 0 and the result cannot be truncated to int32.
     if (op == Token::SHR && constant_value == 0) {
-      if (FLAG_opt_safe_uint32_operations) {
-        does_deopt = !instr->CheckFlag(HInstruction::kUint32);
-      } else {
-        does_deopt = !instr->CheckUsesForFlag(HValue::kTruncatingToInt32);
-      }
+      does_deopt = !instr->CheckFlag(HInstruction::kUint32);
     }
 
     LInstruction* result =