Move RuntimeHelpers.GetRawData and RawData class to shared location

src/coreclr/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.CoreCLR.cs

@@ -185,9 +185,6 @@ internal static int EnumCompareTo<T>(T x, T y) where T : struct, Enum
             return x.CompareTo(y);
         }
 
-        internal static ref byte GetRawData(this object obj) =>
-            ref Unsafe.As<RawData>(obj).Data;
-
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal static unsafe nuint GetRawObjectDataSize(object obj)
         {
@@ -335,12 +332,6 @@ private static unsafe void DispatchTailCalls(
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal static extern int GetMethodsJittedCount();
     }
-    // Helper class to assist with unsafe pinning of arbitrary objects.
-    // It's used by VM code.
-    internal class RawData
-    {
-        public byte Data;
-    }
 
     // CLR arrays are laid out in memory as follows (multidimensional array bounds are optional):
     // [ sync block || pMethodTable || num components || MD array bounds || array data .. ]

src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.cs

@@ -132,5 +132,14 @@ public static void PrepareConstrainedRegionsNoOP()
         internal static bool IsPrimitiveType(this CorElementType et)
             // COR_ELEMENT_TYPE_I1,I2,I4,I8,U1,U2,U4,U8,R4,R8,I,U,CHAR,BOOLEAN
             => ((1 << (int)et) & 0b_0011_0000_0000_0011_1111_1111_1100) != 0;
+
+        internal static ref byte GetRawData(this object obj) =>
+            ref Unsafe.As<RawData>(obj).Data;
+    }
+    // Helper class to assist with unsafe pinning of arbitrary objects.
+    // It's used by VM code.
+    internal class RawData
+    {
+        public byte Data;
     }
 }

src/mono/netcore/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.Mono.cs

@@ -1,6 +1,5 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
-using Internal.Runtime.CompilerServices;
 
 namespace System.Runtime.CompilerServices
 {
@@ -55,16 +54,6 @@ public static void RunClassConstructor(RuntimeTypeHandle type)
             RunClassConstructor(type.Value);
         }
 
-        internal static ref byte GetRawData(this object obj) =>
-            ref Unsafe.As<RawData>(obj).Data;
-
-        // Helper class to assist with unsafe pinning of arbitrary objects.
-        // It's used by VM code.
-        internal class RawData
-        {
-            public byte Data;
-        }
-
         public static void EnsureSufficientExecutionStack()
         {
             if (SufficientExecutionStack())