     @usableFromInline // c-abi
     internal var reg_save_area: UnsafeMutablePointer<Int>?
   }
+
+  @usableFromInline // c-abi
+  internal var gpRegistersUsed = 0
+  @usableFromInline // c-abi
+  internal var fpRegistersUsed = 0
+
+  @usableFromInline // c-abi
+  final  // Property must be final since it is used by Builtin.addressof.
+  internal var header = Header()
+  @usableFromInline // c-abi
+  internal var storage: ContiguousArray<Int>
 
   @inlinable // c-abi
   internal init() {

             _fromUnsafeMutablePointer: UnsafeMutableRawPointer(
               Builtin.addressof(&self.header)))
  }

  @usableFromInline // c-abi
  internal var gpRegistersUsed = 0
  @usableFromInline // c-abi
  internal var fpRegistersUsed = 0

  @usableFromInline // c-abi
  final  // Property must be final since it is used by Builtin.addressof.
  internal var header = Header()
  @usableFromInline // c-abi
  internal var storage: ContiguousArray<Int>
}

#else

/// An object that can manage the lifetime of storage backing a
/// `CVaListPointer`.
@_fixed_layout // FIXME(sil-serialize-all)
@_fixed_layout // c-abi
@usableFromInline // c-abi
final internal class _VaListBuilder {



/// An object that can manage the lifetime of storage backing a
/// `CVaListPointer`.
@_fixed_layout
@usableFromInline // c-abi
final internal class _VaListBuilder {
  @_fixed_layout // c-abi
  @usableFromInline
  internal struct Header {
