Remove FLAG_opt_safe_uint32_operations.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index c9a23fd22868f928df88ac0474cadae1bdb6341d..8b20e86c70a60c6f5d73a49991873354d7cfdb34 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -739,11 +739,7 @@ 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 =