xbps-src: added XBPS_LDFLAGS into the configuration file.

This is to specify common LDFLAGS settings for all packages, by default
it's set to '-Wl,--as-needed' to avoid linking extra libraries into
the binaries. This helped to find such cases.

xbps-src/shutils/chroot.sh.in

@@ -61,6 +61,7 @@ XBPS_DISTRIBUTIONDIR=/xbps
 XBPS_MASTERDIR=/
 XBPS_CFLAGS="$XBPS_CFLAGS"
 XBPS_CXXFLAGS="$XBPS_CFLAGS"
+XBPS_LDFLAGS="$XBPS_LDFLAGS"
 XBPS_FETCH_CMD="xbps-uhelper.static fetch"
 XBPS_COMPRESS_CMD="$XBPS_COMPRESS_CMD"
 _EOF