Fix #1635: DynamicInvokeConstructorInstruction Did report the wrong StackType for value types and unknown types.

ICSharpCode.Decompiler.Tests/TestCases/Pretty/DynamicTests.cs

@@ -415,6 +415,11 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 			return true.Equals(a);
 		}
 
+		private static IntPtr NewIntPtr(dynamic a)
+		{
+			return new IntPtr(a);
+		}
+
 		private static dynamic GetDynamic(int i)
 		{
 			return null;

ICSharpCode.Decompiler/IL/Instructions/DynamicInstructions.cs

@@ -349,14 +349,17 @@ namespace ICSharpCode.Decompiler.IL
 
 	partial class DynamicInvokeConstructorInstruction
 	{
+		readonly IType resultType;
+
 		public IReadOnlyList<CSharpArgumentInfo> ArgumentInfo { get; }
 
-		public DynamicInvokeConstructorInstruction(CSharpBinderFlags binderFlags, IType context, CSharpArgumentInfo[] argumentInfo, ILInstruction[] arguments)
+		public DynamicInvokeConstructorInstruction(CSharpBinderFlags binderFlags, IType type, IType context, CSharpArgumentInfo[] argumentInfo, ILInstruction[] arguments)
 			: base(OpCode.DynamicInvokeConstructorInstruction, binderFlags, context)
 		{
 			ArgumentInfo = argumentInfo;
 			Arguments = new InstructionCollection<ILInstruction>(this, 0);
 			Arguments.AddRange(arguments);
+			this.resultType = type;
 		}
 
 		public override void WriteTo(ITextOutput output, ILAstWritingOptions options)
@@ -365,11 +368,12 @@ namespace ICSharpCode.Decompiler.IL
 			output.Write(OpCode);
 			WriteBinderFlags(output, options);
 			output.Write(' ');
+			resultType?.WriteTo(output);
 			output.Write(".ctor");
 			WriteArgumentList(output, options, Arguments.Zip(ArgumentInfo));
 		}
 
-		public override StackType ResultType => StackType.O;
+		public override StackType ResultType => resultType?.GetStackType() ?? StackType.Unknown;
 
 		public override CSharpArgumentInfo GetArgumentInfoOfChild(int index)
 		{

ICSharpCode.Decompiler/IL/Transforms/DynamicCallSiteTransform.cs

@@ -183,12 +183,23 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 						arguments: targetInvokeCall.Arguments.Skip(2).ToArray()
 					);
 				case BinderMethodKind.InvokeConstructor:
+					var arguments = targetInvokeCall.Arguments.Skip(2).ToArray();
+					// Extract type information from targetInvokeCall:
+					// Must either be an inlined type or
+					// a reference to a variable that is initialized with a type.
+					if (!TransformExpressionTrees.MatchGetTypeFromHandle(arguments[0], out var type)) {
+						if (!(arguments[0].MatchLdLoc(out var temp) && temp.IsSingleDefinition && temp.StoreInstructions.FirstOrDefault() is StLoc initStore))
+							return null;
+						if (!TransformExpressionTrees.MatchGetTypeFromHandle(initStore.Value, out type))
+							return null;
+					}
 					deadArguments.AddRange(targetInvokeCall.Arguments.Take(2));
 					return new DynamicInvokeConstructorInstruction(
 						binderFlags: callsite.Flags,
+						type: type ?? SpecialType.UnknownType,
 						context: callsite.Context,
 						argumentInfo: callsite.ArgumentInfos,
-						arguments: targetInvokeCall.Arguments.Skip(2).ToArray()
+						arguments: arguments
 					);
 				case BinderMethodKind.InvokeMember:
 					deadArguments.AddRange(targetInvokeCall.Arguments.Take(2));