[crankshaft] Remove the useless HCallStub instruction.

src/crankshaft/arm64/lithium-arm64.h

Index: src/crankshaft/arm64/lithium-arm64.h
diff --git a/src/crankshaft/arm64/lithium-arm64.h b/src/crankshaft/arm64/lithium-arm64.h
index 5a1bc701c712372124b9c87f26ee0de845caf875..e7b59245f4f3440263528010b6d89b65cac09ffe 100644
--- a/src/crankshaft/arm64/lithium-arm64.h
+++ b/src/crankshaft/arm64/lithium-arm64.h
@@ -37,7 +37,6 @@ class LCodeGen;
   V(CallJSFunction)                          \
   V(CallNewArray)                            \
   V(CallRuntime)                             \
-  V(CallStub)                                \
   V(CallWithDescriptor)                      \
   V(CheckArrayBufferNotNeutered)             \
   V(CheckInstanceType)                       \
@@ -883,19 +882,6 @@ class LCallRuntime final : public LTemplateInstruction<1, 1, 0> {
 };
 
 
-class LCallStub final : public LTemplateInstruction<1, 1, 0> {
- public:
-  explicit LCallStub(LOperand* context) {
-    inputs_[0] = context;
-  }
-
-  LOperand* context() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CallStub, "call-stub")
-  DECLARE_HYDROGEN_ACCESSOR(CallStub)
-};
-
-
 class LCheckArrayBufferNotNeutered final
     : public LTemplateInstruction<0, 1, 0> {
  public: