pgsql: Don't trash input list structure in does_not_exist_skipping().

Don't trash input list structure in does_not_exist_skipping().

The trigger and rule cases need to split up the input name list, but
they mustn't corrupt the passed-in data structure, since it could be part
of a cached utility-statement parsetree. Per bug #7641.

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/03787f63921e37c123ceff712ed405c5172e765d

Modified Files
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src/backend/commands/dropcmds.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)