Fix #1773: Remove copies of parameter values only if the types match exactly.

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

@@ -385,5 +385,11 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 				return captured.FirstOrDefault();
 			};
 		}
+
+		public static Func<int> Issue1773(short data)
+		{
+			int integerData = data;
+			return () => integerData;
+		}
 	}
 }

ICSharpCode.Decompiler/IL/Transforms/TransformDisplayClassUsage.cs

@@ -322,7 +322,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			parameter = null;
 			if (!IsDisplayClassFieldAccess(inst.Target, out var displayClassVar, out displayClass, out field))
 				return false;
-			if (!(inst.Value.MatchLdLoc(out var v) && v.Kind == VariableKind.Parameter && v.Function == currentFunction))
+			if (!(inst.Value.MatchLdLoc(out var v) && v.Kind == VariableKind.Parameter && v.Function == currentFunction && v.Type.Equals(field.Type)))
 				return false;
 			if (displayClass.Variables.ContainsKey((IField)field.MemberDefinition))
 				return false;