pg_upgrade: clarify C comment about Windows thread struct pointers
Backpatch to 9.3 to keep source trees consistent.
Branch
------
REL9_3_STABLE
Details
-------
http://git.postgresql.org/pg/commitdiff/e243e3a42887f82be6dc5a6bf6e8534a733b8bc8
Modified Files
--------------
contrib/pg_upgrade/parallel.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)