-fno-common is the new default in GCC 10, replacing -fcommon in
GCC <= 9, so static data must only be allocated once.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Romain Dolbeau <romain.dolbeau@european-processor-initiative.eu>
Closes#9943
af09c050e9