build-package.sh: create dummy libutil.so which links to libc

Replace libutil.so with linker script so we don't have to patch
each program that tries to link with libutil.so.

scripts/build/termux_step_extract_into_massagedir.sh

@@ -5,6 +5,7 @@ termux_step_extract_into_massagedir() {
 	cd $TERMUX_PREFIX
 	tar -N "$TERMUX_BUILD_TS_FILE" \
 		--exclude='lib/libc++_shared.so' --exclude='lib/libstdc++.so' \
+		--exclude='lib/libutil.so' \
 		-czf "$TARBALL_ORIG" .
 
 	# Extract tar in order to massage it

scripts/build/termux_step_setup_toolchain.sh

@@ -155,6 +155,13 @@ termux_step_setup_toolchain() {
 		mv $_TERMUX_TOOLCHAIN_TMPDIR $TERMUX_STANDALONE_TOOLCHAIN
 	fi
 
+	# On Android 7, libutil functionality is provided by libc.
+	# But many programs still may search for libutil.
+	if [ ! -f $TERMUX_PREFIX/lib/libutil.so ]; then
+		mkdir -p "$TERMUX_PREFIX/lib"
+		echo 'INPUT(-lc)' > $TERMUX_PREFIX/lib/libutil.so
+	fi
+
 	local _STL_LIBFILE_NAME=libc++_shared.so
 	if [ ! -f $TERMUX_PREFIX/lib/libstdc++.so ]; then
 		# Setup libc++_shared.so in $PREFIX/lib and libstdc++.so as a link to it,