pgsql: Add some isolation tests for deadlock detection and resolution.

Add some isolation tests for deadlock detection and resolution.

Previously, we had no test coverage for the deadlock detector.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/4c9864b9b4d87d02f07f40bb27976da737afdcab

Modified Files
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src/test/isolation/expected/deadlock-hard.out | 35 +++++++++++++
src/test/isolation/expected/deadlock-simple.out | 11 ++++
src/test/isolation/expected/deadlock-soft-2.out | 17 ++++++
src/test/isolation/expected/deadlock-soft.out | 17 ++++++
src/test/isolation/isolation_schedule | 4 ++
src/test/isolation/specs/deadlock-hard.spec | 70 +++++++++++++++++++++++++
src/test/isolation/specs/deadlock-simple.spec | 29 ++++++++++
src/test/isolation/specs/deadlock-soft-2.spec | 38 ++++++++++++++
src/test/isolation/specs/deadlock-soft.spec | 40 ++++++++++++++
9 files changed, 261 insertions(+)