* gnu/packages/patches/transfig-gcc10-fno-common.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/xfig.scm (transfig)[source]<origin>: Use patch
"transfig-gcc10-fno-common.patch" to avoid "multiple definition" errors with
GCC 10+ and "-f-no-common".
Signed-off-by: Ludovic Courtès <ludo@gnu.org>