Speculate on bitwise operators.

runtime/vm/intermediate_language_arm64.cc

Index: runtime/vm/intermediate_language_arm64.cc
diff --git a/runtime/vm/intermediate_language_arm64.cc b/runtime/vm/intermediate_language_arm64.cc
index 5e4e500aaf956161cdf0cb3b24bca08103c9d64a..55ab8605bd0d04ad2ca5044d986680eeeb5a4c0b 100644
--- a/runtime/vm/intermediate_language_arm64.cc
+++ b/runtime/vm/intermediate_language_arm64.cc
@@ -2904,6 +2904,31 @@ void CheckedSmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     case Token::kBIT_XOR:
       __ eor(result, left, Operand(right));
       break;
+    case Token::kSHL:
+      ASSERT(result != left);
+      ASSERT(result != right);
+      __ CompareImmediate(right,
+                          reinterpret_cast<int64_t>(Smi::New(Smi::kBits)));
+      __ b(slow_path->entry_label(), CS);
+
+      __ SmiUntag(TMP, right);
+      __ lslv(result, left, TMP);
+      __ asrv(TMP2, result, TMP);
+      __ CompareRegisters(left, TMP2);
+      __ b(slow_path->entry_label(), NE);  // Overflow.
+      break;
+    case Token::kSHR:
+      ASSERT(result != left);
+      ASSERT(result != right);
+      __ CompareImmediate(right,
+                          reinterpret_cast<int64_t>(Smi::New(Smi::kBits)));
+      __ b(slow_path->entry_label(), CS);
+
+      __ SmiUntag(result, right);
+      __ SmiUntag(TMP, left);
+      __ asrv(result, TMP, result);
+      __ SmiTag(result);
+      break;
     default:
       UNIMPLEMENTED();
   }