[crankshaft] Remove the useless HAllocateBlockContext instruction.

src/crankshaft/x87/lithium-x87.cc

Index: src/crankshaft/x87/lithium-x87.cc
diff --git a/src/crankshaft/x87/lithium-x87.cc b/src/crankshaft/x87/lithium-x87.cc
index a7fdc7495db4bd5bb29dc1dfad8329bbdfdfc073..3b3794432421ecae6e53588c6981eb7ab56c9481 100644
--- a/src/crankshaft/x87/lithium-x87.cc
+++ b/src/crankshaft/x87/lithium-x87.cc
@@ -2671,16 +2671,6 @@ LInstruction* LChunkBuilder::DoStoreFrameContext(HStoreFrameContext* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoAllocateBlockContext(
-    HAllocateBlockContext* instr) {
-  LOperand* context = UseFixed(instr->context(), esi);
-  LOperand* function = UseRegisterAtStart(instr->function());
-  LAllocateBlockContext* result =
-      new(zone()) LAllocateBlockContext(context, function);
-  return MarkAsCall(DefineFixed(result, esi), instr);
-}
-
-
 }  // namespace internal
 }  // namespace v8