pgsql: Add missing CHECK_FOR_INTERRUPTS in lseg_inside_poly

Add missing CHECK_FOR_INTERRUPTS in lseg_inside_poly

Apparently, there are bugs in this code that cause it to loop endlessly.
That bug still needs more research, but in the meantime it's clear that
the loop is missing a check for interrupts so that it can be cancelled
timely.

Backpatch to 9.1 -- this has been missing since 49475aab8d0d.

Branch
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REL9_4_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/b9a46f8ba667556b7a9b34c8c36f5d465f3fc7a2

Modified Files
--------------
src/backend/utils/adt/geo_ops.c |    3 +++
1 file changed, 3 insertions(+)