How to put an accent mark on a barred i (U+0268) without the tittle/dot
This seems quite enough for the standard sizes.
\documentclass{article}
\usepackage{tipa}
\usepackage{pict2e,picture}
\usepackage{color}
\makeatletter
\newcommand{\textdotlessbari}[1]{%
\begingroup
\settowidth\dimen@{\textbari}%
\makebox[\dimen@]{%
\sbox\z@{\i}%
\begin{picture}(0,\ht\z@)
\roundcap
\linethickness{0.055ex}
\put(0.05\wd\z@,0.55\ht\z@){\line(1,0){0.9\wd\z@}}
\end{picture}%
#1\i
}%
\endgroup
}
\DeclareRobustCommand{\textbariacute}{\textdotlessbari{\'}}
\DeclareRobustCommand{\textbarigrave}{\textdotlessbari{\`}}
\makeatother
\begin{document}
--\textbari--
--\textbariacute--
\leavevmode
\rlap{\textcolor{red}{\textbari}}\textbariacute
\rlap{\textcolor{red}{\textbariacute}}\textbari
\textbariacute\textbarigrave\textdotlessbari{\~}
\Huge
--\textbari--
--\textbariacute--
\leavevmode
\rlap{\textcolor{red}{\textbari}}\textbariacute
\rlap{\textcolor{red}{\textbariacute}}\textbari
\textbariacute\textbarigrave\textdotlessbari{\~}
\end{document}
The third line shows the characters superimposed to one another in different color and the differences are very small to be really noticeable.
Use \rlap{-}\'\i
or \leavevmode\rlap{-}\'\i
if that symbol start a paragraph. Example:
\documentclass[12pt]{article}
\begin{document}
\leavevmode\rlap{-}\'\i p ip \rlap{-}\'\i p ip
\end{document}