VM: Add smi fast path operations for precompiled code

runtime/vm/constant_propagator.cc

Index: runtime/vm/constant_propagator.cc
diff --git a/runtime/vm/constant_propagator.cc b/runtime/vm/constant_propagator.cc
index fa21b0fc9e30df3cc51e17401477b572c6e5d037..03ab8ae7c39aaac71cd94b8d91ebd85cd255fbc0 100644
--- a/runtime/vm/constant_propagator.cc
+++ b/runtime/vm/constant_propagator.cc
@@ -937,6 +937,11 @@ void ConstantPropagator::VisitBinaryIntegerOp(BinaryIntegerOpInstr* binary_op) {
 }
 
 
+void ConstantPropagator::VisitCheckedSmiOp(CheckedSmiOpInstr* instr) {
+  SetValue(instr, non_constant_);
+}
+
+
 void ConstantPropagator::VisitBinarySmiOp(BinarySmiOpInstr* instr) {
   VisitBinaryIntegerOp(instr);
 }