Re: extend pgbench expressions with functions

Hello Michaël,

>> I'll be happy if you do the review of the resulting split.
>
> OK, I am fine with this scenario as well. I have luckily done nothing yet.

Here is a 3 part v29:

a) add support for integer functions in pgbench, including turning
operators as functions, as well as some minimal infrastructure for
additional types (this allows to minimize the diffs with the next
patch which adds double).

b) add support for doubles, including setting double variables.
Note that variable are not explicitely typed. Add some
double-related functions, most interesting of them for pgbench
are the randoms.

c) remove \setrandom support (as thanks to part b \set x random(...) does
the same). Prints an error pointing to the replacement if \setrandom is
used in a pgbench script.

--
Fabien.