pgsql: Fix inline_set_returning_function() to preserve the invalItems l

Fix inline_set_returning_function() to preserve the invalItems list properly.

This avoids a possible crash when inlining a SRF whose argument list
contains a reference to an inline-able user function. The crash is quite
reproducible with CLOBBER_FREED_MEMORY enabled, but would be less certain
in a production build. Problem introduced in 9.0 by the named-arguments
patch, which requires invoking eval_const_expressions() before we can try
to inline a SRF. Per report from Brendan Jurd.

Branch
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REL9_0_STABLE

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=113082c6579f3310ecaa6a5cba2e24a0ce325b5d

Modified Files
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src/backend/optimizer/util/clauses.c | 23 ++++++++++++++++++++++-
1 files changed, 22 insertions(+), 1 deletions(-)