Delete HAbnormalExit. It does more harm than good.

src/x64/lithium-x64.cc

 // 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 1771 matching lines @@
 }
 
 
 LInstruction* LChunkBuilder::DoBoundsCheckBaseIndexInformation(
     HBoundsCheckBaseIndexInformation* instr) {
   UNREACHABLE();
   return NULL;
 }
 
 
-LInstruction* LChunkBuilder::DoAbnormalExit(HAbnormalExit* instr) {
-  // The control instruction marking the end of a block that completed
-  // abruptly (e.g., threw an exception).  There is nothing specific to do.
-  return NULL;
-}
-
-
 LInstruction* LChunkBuilder::DoThrow(HThrow* instr) {
   LOperand* value = UseFixed(instr->value(), rax);
   return MarkAsCall(new(zone()) LThrow(value), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoUseConst(HUseConst* instr) {
   return NULL;
 }
 
@@ skipping 724 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64