Use concrete types when possible for improved performance

src/ARMeilleure/CodeGen/Arm64/CodeGenContext.cs

@@ -1,6 +1,7 @@
 using ARMeilleure.CodeGen.Linking;
 using ARMeilleure.CodeGen.RegisterAllocators;
 using ARMeilleure.IntermediateRepresentation;
+using Microsoft.IO;
 using Ryujinx.Common.Memory;
 using System;
 using System.Collections.Generic;
@@ -14,7 +15,7 @@ namespace ARMeilleure.CodeGen.Arm64
         private const int CbnzInstLength = 4;
         private const int LdrLitInstLength = 4;
 
-        private readonly Stream _stream;
+        private readonly RecyclableMemoryStream _stream;
 
         public int StreamOffset => (int)_stream.Length;