Add Task-based async API for Socket.SendFile #42591
Description
Background and Motivation
We have an APM version of this and a SocketAsyncEventArgs version, but no Task-based version.
Current APM:
public IAsyncResult BeginSendFile(string fileName, AsyncCallback? callback, object? state);
public IAsyncResult BeginSendFile(string? fileName, byte[]? preBuffer, byte[]? postBuffer, TransmitFileOptions flags, AsyncCallback? callback, object? state); Proposed API
public ValueTask SendFileAsync(string fileName);
public ValueTask SendFileAsync(string? fileName, byte[]? preBuffer, byte[]? postBuffer, TransmitFileOptions flags);