Revert of [turbofan] Add alignment parameter to StackSlot operator

src/compiler/machine-operator.h

Index: src/compiler/machine-operator.h
diff --git a/src/compiler/machine-operator.h b/src/compiler/machine-operator.h
index 82d40a09e3fa39069a04576e64542dda9f27a1e2..b53202e298b264472a16bab0e9d37adc69d7c36d 100644
--- a/src/compiler/machine-operator.h
+++ b/src/compiler/machine-operator.h
@@ -93,29 +93,7 @@
 
 CheckedStoreRepresentation CheckedStoreRepresentationOf(Operator const*);
 
-class StackSlotRepresentation final {
- public:
-  StackSlotRepresentation(int size, int alignment)
-      : size_(size), alignment_(alignment) {}
-
-  int size() const { return size_; }
-  int alignment() const { return alignment_; }
-
- private:
-  int size_;
-  int alignment_;
-};
-
-V8_EXPORT_PRIVATE bool operator==(StackSlotRepresentation,
-                                  StackSlotRepresentation);
-bool operator!=(StackSlotRepresentation, StackSlotRepresentation);
-
-size_t hash_value(StackSlotRepresentation);
-
-V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream&,
-                                           StackSlotRepresentation);
-
-StackSlotRepresentation const& StackSlotRepresentationOf(Operator const* op);
+int StackSlotSizeOf(Operator const* op);
 
 MachineRepresentation AtomicStoreRepresentationOf(Operator const* op);
 
@@ -621,8 +599,8 @@
   // unaligned store [base + index], value
   const Operator* UnalignedStore(UnalignedStoreRepresentation rep);
 
-  const Operator* StackSlot(int size, int alignment = 0);
-  const Operator* StackSlot(MachineRepresentation rep, int alignment = 0);
+  const Operator* StackSlot(int size);
+  const Operator* StackSlot(MachineRepresentation rep);
 
   // Access to the machine stack.
   const Operator* LoadStackPointer();