pgsql: Add tests for error message generation in partition tupleroutin

Add tests for error message generation in partition tuple routing

This adds extra tests for the error message generated for partition
tuple routing in the executor, using more than three levels of
partitioning including partitioned tables with no partitions.  These
tests have been added to fix CVE-2019-10129 on REL_11_STABLE.  HEAD has
no active bugs in this area, but it lacked coverage.

Author: Michael Paquier
Reviewed-by: Noah Misch
Security: CVE-2019-10129

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/91248608a61d5504f8ac46534136de9b3717fed2

Modified Files
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src/test/regress/expected/insert.out | 15 +++++++++++++++
src/test/regress/sql/insert.sql      |  7 +++++++
2 files changed, 22 insertions(+)