Avoid transforming sub pattern of cpblk stackalloc initializer

Author: siegfriedpammer

ICSharpCode.Decompiler/IL/Transforms/TransformArrayInitializers.cs

@@ -137,6 +137,8 @@ internal static bool TransformRuntimeHelpersCreateSpanInitialization(Call inst,
 				return false;
 			if (!field.HasFlag(System.Reflection.FieldAttributes.HasFieldRVA))
 				return false;
+			if (IsSubPatternOfCpblkInitializer(inst))
+				return false;
 			var initialValue = field.GetInitialValue(context.PEFile, context.TypeSystem);
 			var elementTypeSize = elementType.GetSize();
 			if (elementTypeSize <= 0 || initialValue.Length % elementTypeSize != 0)
@@ -146,6 +148,13 @@ internal static bool TransformRuntimeHelpersCreateSpanInitialization(Call inst,
 			return replacement != null;
 		}
 
+		private static bool IsSubPatternOfCpblkInitializer(Call inst)
+		{
+			if (inst.Parent is not AddressOf { Parent: Call { Parent: Cpblk cpblk } get_Item })
+				return false;
+			return MatchGetStaticFieldAddress(get_Item, out _);
+		}
+
 		private static ILInstruction DecodeArrayInitializerOrUTF8StringLiteral(StatementTransformContext context, IType elementType, BlobReader initialValue, int size)
 		{
 			if (context.Settings.Utf8StringLiterals && elementType.IsKnownType(KnownTypeCode.Byte)
@@ -373,7 +382,7 @@ bool HandleCpblkInitializer(Block block, int pos, ILVariable v, long length, out
 			return true;
 		}
 
-		bool MatchGetStaticFieldAddress(ILInstruction input, out IField field)
+		static bool MatchGetStaticFieldAddress(ILInstruction input, out IField field)
 		{
 			if (input.MatchLdsFlda(out field))
 				return true;