Cannot typeset cyrillic text in italics and bold at the same time using the LinuxLibertine font

Apparently Linux Libertine lacks the Cyrillic alphabet in the bold italic font, but it has it in the semibold italic font. So a workaround is to use semibold instead of bold:

\documentclass{article}
\usepackage{fontspec}
\begin{document}
\setmainfont[
  Path              = /usr/local/texlive/2014/texmf-dist/fonts/opentype/public/libertine/,
  Extension         = .otf,
  BoldFont          = LinLibertine_RZ,
  ItalicFont        = LinLibertine_RI,
  BoldItalicFont    = LinLibertine_RZI,
]{LinLibertine_R}
\raggedright
Regular: положим\\
Bold: \textbf{положим}\\
Italic: \textit{положим}\\
Bold+Italic: \textit{\textbf{положим}}
\end{document}

Update

Things have changed; with TeX Live 2017, the following document shows bold italic Cyrillic with no special setup. I also added the same with Libertinus Serif (of course, the \setmainfont declaration should be given just once, with the preferred font).

\documentclass{article}
\usepackage{fontspec}
\setmainfont{Linux Libertine O}

\begin{document}

\raggedright

Regular: положим\\
Bold: \textbf{положим}\\
Italic: \textit{положим}\\
Bold+Italic: \textit{\textbf{положим}}

\setmainfont{Libertinus Serif}

Regular: положим\\
Bold: \textbf{положим}\\
Italic: \textit{положим}\\
Bold+Italic: \textit{\textbf{положим}}

\end{document}