DBC: Fix not-stopping/crashing at fast Smi op breakpoints.

runtime/vm/constants_dbc.h

Index: runtime/vm/constants_dbc.h
diff --git a/runtime/vm/constants_dbc.h b/runtime/vm/constants_dbc.h
index e84ae57e8e2fa89c1bc40ed3276c50e41bfce63c..564e96394ab72bf3a7eba93bc426686555cf689e 100644
--- a/runtime/vm/constants_dbc.h
+++ b/runtime/vm/constants_dbc.h
@@ -754,6 +754,23 @@ BYTECODES_LIST(DECLARE_BYTECODE)
     }
   }
 
+  DART_FORCE_INLINE static bool IsFastSmiOpcode(Instr instr) {
+    switch (DecodeOpcode(instr)) {
+      case Bytecode::kAddTOS:
+      case Bytecode::kSubTOS:
+      case Bytecode::kMulTOS:
+      case Bytecode::kBitOrTOS:
+      case Bytecode::kBitAndTOS:
+      case Bytecode::kEqualTOS:
+      case Bytecode::kLessThanTOS:
+      case Bytecode::kGreaterThanTOS:
+        return true;
+
+      default:
+        return false;
+    }
+  }
+
   DART_FORCE_INLINE static uint8_t DecodeArgc(Instr call) {
     ASSERT(IsCallOpcode(call));
     return (call >> 8) & 0xFF;