Add simple FreeType font cache in class ft_manager. * libinterp/corefcn/txt-eng-ft.cc (ft_face_destroyed): New static function. (ft_manager::font_destroyed): New static method. (ft_manager::do_font_destroyed): New method. (ft_manager::ft_key, ft_manager::ft_cache): New typedef's. (ft_manager::cache): New member, storing weak references to loaded fonts. (ft_manager::do_get_font): Look for font into the cache. Use fontconfig and freetype if not found. Insert newly loaded fonts into the cache. Install finalizer to update the cache on font destruction.

#! /bin/sh

if [ $# -ne 1 ]; then
  echo "usage: find-docstring-files TOP-SRCDIR" 1>&2
  exit 1
fi

## if there is a file in the build directory tree, assume it is
## the file we are looking for.  Otherwise, get the one from the
## source tree.

if [ -f "../../scripts/DOCSTRINGS" ]; then
  echo "../../scripts/DOCSTRINGS"
else
  echo "$1/scripts/DOCSTRINGS"
fi

if [ -f "../../libinterp/DOCSTRINGS" ]; then
  echo "../../libinterp/DOCSTRINGS"
else
  echo "$1/libinterp/DOCSTRINGS"
fi