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
------
master

Details
-------
http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=ef55e294e66725c412d55b9689328235141d816d

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