gnuplot: Make 'help' command work (see #2764)

packages/gnuplot/build.sh

@@ -1,7 +1,17 @@
 TERMUX_PKG_HOMEPAGE=http://gnuplot.info/
 TERMUX_PKG_DESCRIPTION="Command-line driven graphing utility"
 TERMUX_PKG_VERSION=5.2.4
+TERMUX_PKG_REVISION=1
 TERMUX_PKG_SHA256=1515f000bd373aaa53b16183f274189d4f5e0ae47d22f434857933d16a4770cb
 TERMUX_PKG_SRCURL=https://downloads.sourceforge.net/project/gnuplot/gnuplot/${TERMUX_PKG_VERSION}/gnuplot-${TERMUX_PKG_VERSION}.tar.gz
 TERMUX_PKG_EXTRA_CONFIGURE_ARGS="--without-x --with-lua=no --with-bitmap-terminals"
 TERMUX_PKG_DEPENDS="libandroid-support, readline, pango, libgd"
+TERMUX_PKG_HOSTBUILD=yes
+
+termux_step_host_build() {
+	"$TERMUX_PKG_SRCDIR/configure"
+
+	make -C docs/ gnuplot.gih
+	mkdir -p $TERMUX_PREFIX/share/gnuplot/5.2/
+	cp ./docs/gnuplot.gih $TERMUX_PREFIX/share/gnuplot/5.2/gnuplot.gih
+}