Add CHECK_FOR_INTERRUPTS when building pruning stepsHEADmaster

Building the partition pruning steps for excessively complex queries
can take some time.  Add CHECK_FOR_INTERRUPTS() to
get_steps_using_prefix_recurse() to allow more timely processing of
interruptions.

Bug: #19692
Reported-by: Qifan Liu <imchifan@163.com>
Discussion: https://postgr.es/m/19692-dacfc57cda5035fc@postgresql.org
Backpatch-through: 14

0 files changed, 0 insertions, 0 deletions