Add check for non-smi to the IL and use it for class checks.

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
===================================================================
--- runtime/vm/intermediate_language_ia32.cc	(revision 11768)
+++ runtime/vm/intermediate_language_ia32.cc	(working copy)
@@ -2100,8 +2100,6 @@
   Label* deopt = compiler->AddDeoptStub(deopt_id(),
                                         kDeoptCheckClass);
   ASSERT(unary_checks().GetReceiverClassIdAt(0) != kSmiCid);
-  __ testl(value, Immediate(kSmiTagMask));
-  __ j(ZERO, deopt);
   __ LoadClassId(temp, value);
   Label is_ok;
   const intptr_t num_checks = unary_checks().NumberOfChecks();
@@ -2134,13 +2132,30 @@
 
 void CheckSmiComp::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register value = locs()->in(0).reg();
-  Label* deopt = compiler->AddDeoptStub(deopt_id(),
-                                        kDeoptCheckSmi);
+  Label* deopt = compiler->AddDeoptStub(deopt_id(), kDeoptCheckSmi);
   __ testl(value, Immediate(kSmiTagMask));
   __ j(NOT_ZERO, deopt);
 }
 
 
+LocationSummary* CheckNonSmiComp::MakeLocationSummary() const {
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  summary->set_in(0, Location::RequiresRegister());
+  return summary;
+}
+
+
+void CheckNonSmiComp::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register value = locs()->in(0).reg();
+  Label* deopt = compiler->AddDeoptStub(deopt_id(), kDeoptCheckNonSmi);
+  __ testl(value, Immediate(kSmiTagMask));
+  __ j(ZERO, deopt);
+}
+
+
 LocationSummary* CheckArrayBoundComp::MakeLocationSummary() const {
   return LocationSummary::Make(2,
                                Location::NoLocation(),