Use pattern expression instead

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -2791,17 +2791,19 @@ namespace ICSharpCode.Decompiler.CSharp
 					// needs to be consistent with logic in ILReader.CreateILVariable
 					pd.Name = "P_" + i;
 				}
+
 				if (settings.AnonymousTypes && parameter.Type.ContainsAnonymousType())
 					anyAnonymousType = true;
+
 				result.Add(pd);
 				i++;
 			}
+
 			// An anonymous type cannot be named, so a lambda with such a parameter must be implicitly typed.
 			// C# also requires all lambda parameters to use the same form (CS0748). Drop every type when the
 			// remaining parameter syntax permits it; otherwise keep the converted declarations as a
 			// best-effort fallback for an unrepresentable signature.
-			if (anyAnonymousType && result.All(p => p.ParameterModifier == ReferenceKind.None
-				&& !p.IsParams && !p.IsScopedRef && p.Attributes.Count == 0 && p.DefaultExpression is null))
+			if (anyAnonymousType && result.All(p => p is { ParameterModifier: ReferenceKind.None, IsParams: false, IsScopedRef: false, Attributes.Count: 0, DefaultExpression: null }))
 			{
 				foreach (var pd in result)
 					pd.Type = null;