[crankshaft] Remove the useless HAllocateBlockContext instruction.

src/crankshaft/arm/lithium-arm.cc

Index: src/crankshaft/arm/lithium-arm.cc
diff --git a/src/crankshaft/arm/lithium-arm.cc b/src/crankshaft/arm/lithium-arm.cc
index 8d178d5ee001692ad9b4826ffc344ce9735a060b..61b59c409e63f593d2a614ff399c234b68ae1fc2 100644
--- a/src/crankshaft/arm/lithium-arm.cc
+++ b/src/crankshaft/arm/lithium-arm.cc
@@ -2601,15 +2601,5 @@ LInstruction* LChunkBuilder::DoStoreFrameContext(HStoreFrameContext* instr) {
   return new(zone()) LStoreFrameContext(context);
 }
 
-
-LInstruction* LChunkBuilder::DoAllocateBlockContext(
-    HAllocateBlockContext* instr) {
-  LOperand* context = UseFixed(instr->context(), cp);
-  LOperand* function = UseRegisterAtStart(instr->function());
-  LAllocateBlockContext* result =
-      new(zone()) LAllocateBlockContext(context, function);
-  return MarkAsCall(DefineFixed(result, cp), instr);
-}
-
 }  // namespace internal
 }  // namespace v8