Add extension method for Framework build

Author: jtschuster

test/Microsoft.NET.TestFramework/Utilities/BitConverterExtensions.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.NET.TestFramework.Utilities
+{
+    internal static class BitConverterExtensions
+    {
+        extension(BitConverter)
+        {
+            public static uint ToUInt32(ReadOnlySpan<byte> value)
+            {
+                var buffer = new byte[4];
+                value.CopyTo(buffer);
+                return BitConverter.ToUInt32(buffer, 0);
+            }
+        }
+    }
+}

test/Microsoft.NET.TestFramework/Utilities/StreamExtensions.cs

@@ -0,0 +1,27 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.NET.TestFramework.Utilities
+{
+    internal static class StreamExtensions
+    {
+        extension(Stream stream)
+        {
+            public void ReadExactly(Span<byte> buffer)
+            {
+                int bytesRead = 0;
+                byte[] arrayBuffer = new byte[buffer.Length];
+                while (bytesRead < buffer.Length)
+                {
+                    int read = stream.Read(arrayBuffer, bytesRead, buffer.Length - bytesRead);
+                    if (read == 0)
+                    {
+                        throw new EndOfStreamException("Unexpected end of stream while reading Mach-O file.");
+                    }
+                    bytesRead += read;
+                }
+                arrayBuffer.CopyTo(buffer);
+            }
+        }
+    }
+}