common: move handling of rdeps, shlib-provides, shlib-requires files

to XBPS_STATEDIR. There's no need for them to pollute PKGDESTDIR. Keep
INSTALL.msg/REMOVE.msg handling as-is for now because it's a little more
complex. Keep the pkglints for these files because xbps still ignores
them.

common/hooks/pre-pkg/99-pkglint.sh

@@ -170,11 +170,11 @@ hook() {
 	fi
 
 	# Check for missing shlibs and SONAME bumps.
-	if [ ! -s "${PKGDESTDIR}/shlib-provides" ]; then
+	if [ ! -s "${XBPS_STATEDIR}/${pkgname}-shlib-provides" ]; then
 		return 0
 	fi
 
-	for filename in $(<${PKGDESTDIR}/shlib-provides); do
+	for filename in $(<"${XBPS_STATEDIR}/${pkgname}-shlib-provides"); do
 		rev=${filename#*.so.}
 		libname=${filename%.so*}
 		_shlib=$(echo "$libname"|sed -E 's|\+|\\+|g')