Fix 11574: Smi is a subtype of parametrizable Compare.

runtime/vm/flow_graph_compiler_arm.cc

Index: runtime/vm/flow_graph_compiler_arm.cc
===================================================================
--- runtime/vm/flow_graph_compiler_arm.cc	(revision 24599)
+++ runtime/vm/flow_graph_compiler_arm.cc	(working copy)
@@ -225,9 +225,17 @@
   const Class& type_class = Class::ZoneHandle(type.type_class());
   ASSERT(type_class.HasTypeArguments());
   const Register kInstanceReg = R0;
-  // A Smi object cannot be the instance of a parameterized class.
+  Error& malformed_error = Error::Handle();
+  const Type& int_type = Type::Handle(Type::IntType());
+  const bool smi_is_ok = int_type.IsSubtypeOf(type, &malformed_error);
+  // Malforrmed type should have been handled at graph construction time.
+  ASSERT(smi_is_ok || malformed_error.IsNull());
   __ tst(kInstanceReg, ShifterOperand(kSmiTagMask));
-  __ b(is_not_instance_lbl, EQ);
+  if (smi_is_ok) {
+    __ b(is_instance_lbl, EQ);
+  } else {
+    __ b(is_not_instance_lbl, EQ);
+  }
   const AbstractTypeArguments& type_arguments =
       AbstractTypeArguments::ZoneHandle(type.arguments());
   const bool is_raw_type = type_arguments.IsNull() ||
@@ -502,7 +510,6 @@
   }
   if (type.IsInstantiated()) {
     const Class& type_class = Class::ZoneHandle(type.type_class());
-    // A Smi object cannot be the instance of a parameterized class.
     // A class equality check is only applicable with a dst type of a
     // non-parameterized class or with a raw dst type of a parameterized class.
     if (type_class.HasTypeArguments()) {