Add to ref

Author: benaadams

src/System.Memory/ref/System.Memory.cs

@@ -494,12 +494,18 @@ public static partial class Utf8Parser
 }
 namespace System.Runtime.InteropServices
 {
+    using System.Buffers;
+
     public static partial class MemoryMarshal
     {
         public static System.Memory<T> AsMemory<T>(System.ReadOnlyMemory<T> readOnlyMemory) { throw null; }
         public static ref T GetReference<T>(System.ReadOnlySpan<T> span) { throw null; }
         public static ref T GetReference<T>(System.Span<T> span) { throw null; }
         public static bool TryGetArray<T>(System.ReadOnlyMemory<T> readOnlyMemory, out System.ArraySegment<T> arraySegment) { throw null; }
+        public static bool TryGetOwnedMemory<T, TOwner>(ReadOnlyMemory<T> readOnlyMemory, out TOwner ownedMemory)
+            where TOwner : OwnedMemory<T> { throw null; }
+        public static bool TryGetOwnedMemory<T, TOwner>(ReadOnlyMemory<T> readOnlyMemory, out TOwner ownedMemory, out int index, out int length)
+            where TOwner : OwnedMemory<T> { throw null; }
         public static System.Collections.Generic.IEnumerable<T> ToEnumerable<T>(ReadOnlyMemory<T> memory) { throw null; }
         public static System.ReadOnlySpan<TTo> Cast<TFrom, TTo>(System.ReadOnlySpan<TFrom> source) where TFrom : struct where TTo : struct { throw null; }
         public static System.Span<TTo> Cast<TFrom, TTo>(System.Span<TFrom> source) where TFrom : struct where TTo : struct { throw null; }