Update Windows ReadFile and WriteFile to recognise Access Denied error when a read or write is attempted on a disconnected virtual com port

Author: psbob

lib/std/os/windows.zig

@@ -602,6 +602,9 @@ pub const ReadFileError = error{
  OperationAborted,
  /// Unable to read file due to lock.
  LockViolation,
+ /// Known to be possible when:
+ /// - Unable to read from disconnected virtual com port (Windows)
+ AccessDenied,
  Unexpected,
 };
 
@@ -634,6 +637,7 @@ pub fn ReadFile(in_hFile: HANDLE, buffer: []u8, offset: ?u64) ReadFileError!usiz
  .HANDLE_EOF => return 0,
  .NETNAME_DELETED => return error.ConnectionResetByPeer,
  .LOCK_VIOLATION => return error.LockViolation,
+ .ACCESS_DENIED => return error.AccessDenied,
  else => |err| return unexpectedError(err),
  }
  }
@@ -651,6 +655,9 @@ pub const WriteFileError = error{
  LockViolation,
  /// The specified network name is no longer available.
  ConnectionResetByPeer,
+ /// Known to be possible when:
+ /// - Unable to write to disconnected virtual com port (Windows)
+ AccessDenied,
  Unexpected,
 };
 
@@ -687,6 +694,7 @@ pub fn WriteFile(
  .INVALID_HANDLE => return error.NotOpenForWriting,
  .LOCK_VIOLATION => return error.LockViolation,
  .NETNAME_DELETED => return error.ConnectionResetByPeer,
+ .ACCESS_DENIED => return error.AccessDenied,
  else => |err| return unexpectedError(err),
  }
  }