Delete HAbnormalExit. It does more harm than good.

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 45 matching lines @@
 
 #define HYDROGEN_ABSTRACT_INSTRUCTION_LIST(V)  \
   V(ArithmeticBinaryOperation)                 \
   V(BinaryOperation)                           \
   V(BitwiseBinaryOperation)                    \
   V(ControlInstruction)                        \
   V(Instruction)                               \
 
 
 #define HYDROGEN_CONCRETE_INSTRUCTION_LIST(V)  \
-  V(AbnormalExit)                              \
   V(AccessArgumentsAt)                         \
   V(Add)                                       \
   V(Allocate)                                  \
   V(ApplyArguments)                            \
   V(ArgumentsElements)                         \
   V(ArgumentsLength)                           \
   V(ArgumentsObject)                           \
   V(Bitwise)                                   \
   V(BlockEntry)                                \
   V(BoundsCheck)                               \
@@ skipping 1359 matching lines @@
 
  private:
   HReturn(HValue* value, HValue* context, HValue* parameter_count) {
     SetOperandAt(0, value);
     SetOperandAt(1, context);
     SetOperandAt(2, parameter_count);
   }
 };
 
 
-class HAbnormalExit V8_FINAL : public HTemplateControlInstruction<0, 0> {
- public:
-  virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
-    return Representation::None();
-  }
-
-  DECLARE_CONCRETE_INSTRUCTION(AbnormalExit)
-};
-
-
 class HUnaryOperation : public HTemplateInstruction<1> {
  public:
   HUnaryOperation(HValue* value, HType type = HType::Tagged())
       : HTemplateInstruction<1>(type) {
     SetOperandAt(0, value);
   }
 
   static HUnaryOperation* cast(HValue* value) {
     return reinterpret_cast<HUnaryOperation*>(value);
   }
@@ skipping 5473 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_