Avoid escaping all non-ASCII characters.

This change updates the set of special chars to not include non-ASCII
chars.

The previous set of special chars to escape was previously defined by a
list of characters *not* to escape, which included only ASCII
characters. This meant that anything non-ascii would be escaped, and
unnecessarily so since these characters are not special for bash.

Author: szermatt

bash-completion.el

@@ -253,7 +253,7 @@ explanation.")
 Mapping between remote paths as returned by `file-remote-p' and
 Bash processes.")
 
-(defconst bash-completion-special-chars "[^-0-9a-zA-Z_./\n=]"
+(defconst bash-completion-special-chars "[ -$&-*,:-<>?[-^`{-}]"
   "Regexp of characters that must be escaped or quoted.")
 
 (defconst bash-completion--ps1 "'\t$?\v'"