Remove StringCharCodeAtInstr and handle it as part of LoadIndexed.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 17219)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -272,7 +272,6 @@
   M(UnaryMintOp)                                                               \
   M(CheckArrayBound)                                                           \
   M(Constraint)                                                                \
-  M(StringCharCodeAt)                                                          \
   M(StringFromCharCode)
 
 
@@ -511,7 +510,6 @@
   friend class CheckSmiInstr;
   friend class CheckArrayBoundInstr;
   friend class CheckEitherNonSmiInstr;
-  friend class StringCharCodeAtInstr;
   friend class LICM;
   friend class DoubleToSmiInstr;
   friend class DoubleToDoubleInstr;
@@ -2677,22 +2675,20 @@
 };
 
 
-class StringCharCodeAtInstr : public TemplateDefinition<2> {
+class LoadIndexedInstr : public TemplateDefinition<2> {
  public:
-  StringCharCodeAtInstr(Value* receiver,
-                        Value* index,
-                        intptr_t class_id)
+  LoadIndexedInstr(Value* array, Value* index, intptr_t class_id)
       : class_id_(class_id) {
-    ASSERT(receiver != NULL);
+    ASSERT(array != NULL);
     ASSERT(index != NULL);
-    inputs_[0] = receiver;
+    inputs_[0] = array;
     inputs_[1] = index;
   }
 
-  DECLARE_INSTRUCTION(StringCharCodeAt)
+  DECLARE_INSTRUCTION(LoadIndexed)
   virtual RawAbstractType* CompileType() const;
 
-  Value* receiver() const { return inputs_[0]; }
+  Value* array() const { return inputs_[0]; }
   Value* index() const { return inputs_[1]; }
   intptr_t class_id() const { return class_id_; }
 
@@ -2702,6 +2698,8 @@
 
   virtual intptr_t ResultCid() const;
 
+  virtual Representation representation() const;
+
   virtual bool AttributesEqual(Instruction* other) const;
 
   virtual bool AffectedBySideEffect() const { return true; }
@@ -2711,7 +2709,7 @@
  private:
   const intptr_t class_id_;
 
-  DISALLOW_COPY_AND_ASSIGN(StringCharCodeAtInstr);
+  DISALLOW_COPY_AND_ASSIGN(LoadIndexedInstr);
 };
 
 
@@ -2720,8 +2718,8 @@
   explicit StringFromCharCodeInstr(Value* char_code,
                                    intptr_t cid) : cid_(cid) {
     ASSERT(char_code != NULL);
-    ASSERT(char_code->definition()->IsStringCharCodeAt() &&
-           (char_code->definition()->AsStringCharCodeAt()->class_id() ==
+    ASSERT(char_code->definition()->IsLoadIndexed() &&
+           (char_code->definition()->AsLoadIndexed()->class_id() ==
             kOneByteStringCid));
     inputs_[0] = char_code;
   }
@@ -2748,44 +2746,6 @@
 };
 
 
-class LoadIndexedInstr : public TemplateDefinition<2> {
- public:
-  LoadIndexedInstr(Value* array, Value* index, intptr_t class_id)
-      : class_id_(class_id) {
-    ASSERT(array != NULL);
-    ASSERT(index != NULL);
-    inputs_[0] = array;
-    inputs_[1] = index;
-  }
-
-  DECLARE_INSTRUCTION(LoadIndexed)
-  virtual RawAbstractType* CompileType() const;
-
-  Value* array() const { return inputs_[0]; }
-  Value* index() const { return inputs_[1]; }
-  intptr_t class_id() const { return class_id_; }
-
-  virtual bool CanDeoptimize() const { return false; }
-
-  virtual bool HasSideEffect() const { return false; }
-
-  virtual intptr_t ResultCid() const;
-
-  virtual Representation representation() const;
-
-  virtual bool AttributesEqual(Instruction* other) const;
-
-  virtual bool AffectedBySideEffect() const { return true; }
-
-  virtual void InferRange();
-
- private:
-  const intptr_t class_id_;
-
-  DISALLOW_COPY_AND_ASSIGN(LoadIndexedInstr);
-};
-
-
 class StoreIndexedInstr : public TemplateDefinition<3> {
  public:
   StoreIndexedInstr(Value* array,