Mirror changes from dotnet/coreclr (#28534)

* Adding Memory.Pin() to eventually replace Memory.Retain(bool) (#17269)

* Adding Memory.Pin() to eventually replace Memory.Retain(bool)

* Fix copy/paste error and return default for when object is null.

* Fix XML comments.

Signed-off-by: dotnet-bot-corefx-mirror <dotnet-bot@microsoft.com>

* Add Memory.Pin to the ref and add tests.

* Add Pin tests

* Update calls to Retain(true) to now call Pin()

* Remove extra space in tests.

* Add Pin to the ApiCompatBaseline for uapaot.

2 files changed, 6 insertions, 0 deletions

diff --git a/src/System.Runtime/ref/System.Runtime.cs b/src/System.Runtime/ref/System.Runtime.cs
index eb92a61fce..a5e6822783 100644
--- a/src/System.Runtime/ref/System.Runtime.cs
+++ b/src/System.Runtime/ref/System.Runtime.cs
@@ -1700,6 +1700,7 @@ namespace System
         public static implicit operator System.Memory<T> (System.ArraySegment<T> segment) { throw null; }
         public static implicit operator System.ReadOnlyMemory<T> (System.Memory<T> memory) { throw null; }
         public static implicit operator System.Memory<T> (T[] array) { throw null; }
+        public System.Buffers.MemoryHandle Pin() { throw null; }
         public System.Buffers.MemoryHandle Retain(bool pin = false) { throw null; }
         public System.Memory<T> Slice(int start) { throw null; }
         public System.Memory<T> Slice(int start, int length) { throw null; }
@@ -1947,6 +1948,7 @@ namespace System
         public override int GetHashCode() { throw null; }
         public static implicit operator System.ReadOnlyMemory<T> (System.ArraySegment<T> segment) { throw null; }
         public static implicit operator System.ReadOnlyMemory<T> (T[] array) { throw null; }
+        public System.Buffers.MemoryHandle Pin() { throw null; }
         public System.Buffers.MemoryHandle Retain(bool pin = false) { throw null; }
         public System.ReadOnlyMemory<T> Slice(int start) { throw null; }
         public System.ReadOnlyMemory<T> Slice(int start, int length) { throw null; }
diff --git a/src/System.Runtime/src/ApiCompatBaseline.uapaot.txt b/src/System.Runtime/src/ApiCompatBaseline.uapaot.txt
new file mode 100644
index 0000000000..ba98be8651
--- /dev/null
+++ b/src/System.Runtime/src/ApiCompatBaseline.uapaot.txt
@@ -0,0 +1,4 @@
+Compat issues with assembly System.Runtime:
+MembersMustExist : Member 'System.Memory<T>.Pin()' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'System.ReadOnlyMemory<T>.Pin()' does not exist in the implementation but it does exist in the contract.
+Total Issues: 2