pgsql: Check for interrupts and stack overflow during rule/view dumps.

Check for interrupts and stack overflow during rule/view dumps.

Since ruleutils.c recurses, it could be driven to stack overflow by
deeply nested constructs.  Very large queries might also take long
enough to deparse that a check for interrupts seems like a good idea.
Stick appropriate tests into a couple of key places.

Noted by Greg Stark.  Back-patch to all supported branches.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/0bff398761b5e6119b40550bbe3751f4194dc7a7

Modified Files
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src/backend/utils/adt/ruleutils.c |   13 +++++++++++++
1 file changed, 13 insertions(+)