pgsql: Apply patch for test_fsync to add tests for O_DIRECT.

Apply patch for test_fsync to add tests for O_DIRECT.

Adjusted patch by Josh Berkus

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=677b06ca462ec6fd98da9369a2eae6085c9d7fed

Modified Files
--------------
src/tools/fsync/Makefile | 4 +-
src/tools/fsync/README | 21 +++-
src/tools/fsync/test_fsync.c | 256 ++++++++++++++++++++++++++++++++++++++----
3 files changed, 249 insertions(+), 32 deletions(-)