pgsql: Allow callers of create_foreignscan_path to specify nondefault P

Allow callers of create_foreignscan_path to specify nondefault PathTarget.

Although the default choice of rel->reltarget should typically be
sufficient for scan or join paths, it's not at all sufficient for the
purposes PathTargets were invented for; in particular not for
upper-relation Paths. So break API compatibility by adding a PathTarget
argument to create_foreignscan_path(). To ease updating of existing
code, accept a NULL value of the argument as selecting rel->reltarget.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/28048cbaa285b8ac46940e4b39f985d9885fc698

Modified Files
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contrib/file_fdw/file_fdw.c | 1 +
contrib/postgres_fdw/postgres_fdw.c | 4 ++++
src/backend/optimizer/util/pathnode.c | 7 +++++--
src/include/optimizer/pathnode.h | 1 +
4 files changed, 11 insertions(+), 2 deletions(-)