pgsql: pgbench: Support double constants and functions.

pgbench: Support double constants and functions.

The new functions are pi(), random(), random_exponential(),
random_gaussian(), and sqrt(). I was worried that this would be
slower than before, but, if anything, it actually turns out to be
slightly faster, because we now express the built-in pgbench scripts
using fewer lines; each \setrandom can be merged into a subsequent
\set.

Fabien Coelho

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/86c43f4e22c0771fd0cc6bce2799802c894ee2ec

Modified Files
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doc/src/sgml/ref/pgbench.sgml | 283 +++++++++++++++++---------
src/bin/pgbench/exprparse.y | 43 +++-
src/bin/pgbench/exprscan.l | 5 +
src/bin/pgbench/pgbench.c | 450 ++++++++++++++++++++++++++++++++++--------
src/bin/pgbench/pgbench.h | 35 +++-
5 files changed, 624 insertions(+), 192 deletions(-)