Add explicit smi-checks to smi comparisons.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 11616)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -136,7 +136,7 @@
   }
 
   // Unique id used for deoptimization.
-  intptr_t deopt_id() const {
+  virtual intptr_t deopt_id() const {
     ASSERT(CanDeoptimize());
     return deopt_id_;
   }
@@ -1924,7 +1924,7 @@
 
   Value* value() const { return inputs_[0]; }
 
-  intptr_t deopt_id() const { return original_->deopt_id(); }
+  virtual intptr_t deopt_id() const { return original_->deopt_id(); }
 
   virtual Definition* TryReplace(BindInstr* instr) const;
 
@@ -1939,9 +1939,10 @@
 
 class CheckSmiComp : public TemplateComputation<1> {
  public:
-  CheckSmiComp(Value* value, InstanceCallComp* original)
-      : original_(original) {
+  CheckSmiComp(Value* value, intptr_t original_deopt_id)
+      : original_deopt_id_(original_deopt_id) {
     ASSERT(value != NULL);
+    ASSERT(original_deopt_id != Isolate::kNoDeoptId);
     inputs_[0] = value;
   }
 
@@ -1958,10 +1959,10 @@
 
   Value* value() const { return inputs_[0]; }
 
-  intptr_t deopt_id() const { return original_->deopt_id(); }
+  virtual intptr_t deopt_id() const { return original_deopt_id_; }
 
  private:
-  InstanceCallComp* original_;
+  const intptr_t original_deopt_id_;
 
   DISALLOW_COPY_AND_ASSIGN(CheckSmiComp);
 };
@@ -1994,7 +1995,7 @@
 
   intptr_t array_type() const { return array_type_; }
 
-  intptr_t deopt_id() const { return original_->deopt_id(); }
+  virtual intptr_t deopt_id() const { return original_->deopt_id(); }
 
  private:
   intptr_t array_type_;