pgsql: Improve largeobject regression test to show size of object read

Improve largeobject regression test to show size of object read from file.

The idea here is to provide a more easily diagnosable failure diff when
the problem is that tenk.data has been DOS-ified, as I believe to be
happening currently on buildfarm member hamerkop. Per suggestion from
Magnus Hagander.

Also, sync output/largeobject_1.source with current regression test.
Failure to do that in commit 3a0e4d36ebd7f477822d5bae41ba121a40d22ccc
turns out to be the real reason that hamerkop has been complaining.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/bd9b4f16894b98cffade9a77d87b910a939d10c5

Modified Files
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src/test/regress/input/largeobject.source | 3 ++
src/test/regress/output/largeobject.source | 7 ++++++
src/test/regress/output/largeobject_1.source | 27 ++++++++++++++++++++++++++
3 files changed, 37 insertions(+), 0 deletions(-)