[int64-lowering] Remove unused functions

Bug:v8:7510

R=ahaas@chromium.org

Change-Id: Id3c6b4ebcb89300c4b886c79f4c688bc18648b06
Reviewed-on: https://chromium-review.googlesource.com/1036650
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52924}

src/compiler/int64-lowering.cc

@@ -126,12 +126,6 @@ int Int64Lowering::GetParameterCountAfterLowering(
       signature, static_cast<int>(signature->parameter_count()));
 }
 
-// static
-bool Int64Lowering::IsI64AsTwoParameters(MachineOperatorBuilder* machine,
-                                         MachineRepresentation type) {
-  return machine->Is32() && type == MachineRepresentation::kWord64;
-}
-
 void Int64Lowering::GetIndexNodes(Node* index, Node*& index_low,
                                   Node*& index_high) {
   if (HasReplacementLow(index)) {

src/compiler/int64-lowering.h

@@ -27,11 +27,6 @@ class V8_EXPORT_PRIVATE Int64Lowering {
   static int GetParameterCountAfterLowering(
       Signature<MachineRepresentation>* signature);
 
-  // Determine whether the given type is i64 and has to be passed via two
-  // parameters on the given machine.
-  static bool IsI64AsTwoParameters(MachineOperatorBuilder* machine,
-                                   MachineRepresentation type);
-
  private:
   enum class State : uint8_t { kUnvisited, kOnStack, kVisited };
 
@@ -46,13 +41,11 @@ class V8_EXPORT_PRIVATE Int64Lowering {
   CommonOperatorBuilder* common() const { return common_; }
   Signature<MachineRepresentation>* signature() const { return signature_; }
 
-  void PrepareReplacements(Node* node);
   void PushNode(Node* node);
   void LowerNode(Node* node);
   bool DefaultLowering(Node* node, bool low_word_only = false);
   void LowerComparison(Node* node, const Operator* signed_op,
                        const Operator* unsigned_op);
-  void PrepareProjectionReplacements(Node* node);
 
   void ReplaceNode(Node* old, Node* new_low, Node* new_high);
   bool HasReplacementLow(Node* node);