pgsql: Revert "Use "transient" files for blind writes, take 2".

Revert "Use "transient" files for blind writes, take 2".

This reverts commit fba105b1099f4f5fa7283bb17cba6fed2baa8d0c.
That approach had problems with the smgr-level state not tracking what
we really want to happen, and with the VFD-level state not tracking the
smgr-level state very well either.  In consequence, it was still possible
to hold kernel file descriptors open for long-gone tables (as in recent
report from Tore Halset), and yet there were also cases of FDs being closed
undesirably soon.  A replacement implementation will follow.

Branch
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REL9_1_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/cacb65263b99c3d96aa4b250cdbda05072ade03e

Modified Files
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src/backend/storage/buffer/bufmgr.c |   10 +---
src/backend/storage/file/fd.c       |   91 ++++++++++-------------------------
src/backend/storage/smgr/md.c       |    9 ----
src/backend/storage/smgr/smgr.c     |   17 -------
src/include/storage/fd.h            |    1 -
src/include/storage/smgr.h          |    2 -
6 files changed, 28 insertions(+), 102 deletions(-)