Delete HAbnormalExit. It does more harm than good.

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 5978fad604cd54eb30904d6448b6e84ea09d9c19..fe7150d5284b18eefb1eae3d8166552bd991bd47 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -1872,13 +1872,6 @@ LInstruction* LChunkBuilder::DoBoundsCheckBaseIndexInformation(
 }
 
 
-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(), r0);
   return MarkAsCall(new(zone()) LThrow(value), instr);