BRO1605: Property summary documentation should omit accessor with restricted access

A property whose setter is private or internal is documented as Gets, not Gets or sets: other code can't set it. Replaces StyleCop SA1624.

Example

Before

public class Account
{
    /// <summary>Gets or sets the balance.</summary>
    public decimal Balance { get; private set; }

    public void Deposit(decimal amount) => Balance += amount;
}

After

public class Account
{
    /// <summary>Gets the balance.</summary>
    public decimal Balance { get; private set; }

    public void Deposit(decimal amount) => Balance += amount;
}

Why

Documentation describes what callers can do. For them, a property with a private setter is read-only.

How the fix works

Gets or sets becomes Gets (and Gets or sets a value indicating whether becomes Gets a value indicating whether). The same goes for Gets or initializes on a property with a restricted init accessor. A private, internal or private protected setter counts as restricted; a protected or protected internal one doesn't, since derived types can use it (like StyleCop). The same goes for a restricted getter: { private get; set; } is documented Sets, not Gets or sets.

This rule reads documentation as XML, which needs <GenerateDocumentationFile>true</GenerateDocumentationFile>.

Compared with StyleCop

Same results and fixed output as StyleCop's master (unreleased), which added init accessors (StyleCop 1.2.0-beta.556 ignores them).