[crankshaft] Remove the useless HAllocateBlockContext instruction.

src/crankshaft/x64/lithium-x64.h

Index: src/crankshaft/x64/lithium-x64.h
diff --git a/src/crankshaft/x64/lithium-x64.h b/src/crankshaft/x64/lithium-x64.h
index 76eac9f5c618265b9e9a9381168a9f5cefa5716d..406159b1ff34b0086c96fc839e8c3a638f812ac0 100644
--- a/src/crankshaft/x64/lithium-x64.h
+++ b/src/crankshaft/x64/lithium-x64.h
@@ -21,7 +21,6 @@ class LCodeGen;
   V(AccessArgumentsAt)                       \
   V(AddI)                                    \
   V(Allocate)                                \
-  V(AllocateBlockContext)                    \
   V(ApplyArguments)                          \
   V(ArgumentsElements)                       \
   V(ArgumentsLength)                         \
@@ -2541,23 +2540,6 @@ class LStoreFrameContext: public LTemplateInstruction<0, 1, 0> {
 };
 
 
-class LAllocateBlockContext: public LTemplateInstruction<1, 2, 0> {
- public:
-  LAllocateBlockContext(LOperand* context, LOperand* function) {
-    inputs_[0] = context;
-    inputs_[1] = function;
-  }
-
-  LOperand* context() { return inputs_[0]; }
-  LOperand* function() { return inputs_[1]; }
-
-  Handle<ScopeInfo> scope_info() { return hydrogen()->scope_info(); }
-
-  DECLARE_CONCRETE_INSTRUCTION(AllocateBlockContext, "allocate-block-context")
-  DECLARE_HYDROGEN_ACCESSOR(AllocateBlockContext)
-};
-
-
 class LChunkBuilder;
 class LPlatformChunk final : public LChunk {
  public: