pgsql: Allow backslash line continuations in pgbench's meta commands.

Allow backslash line continuations in pgbench's meta commands.

A pgbench meta command can now be continued onto additional line(s) of a
script file by writing backslash-return. The continuation marker is
equivalent to white space in that it separates tokens.

Eventually it'd be nice to have the same thing in psql, but that will
be a much larger project.

Fabien Coelho, reviewed by Rafia Sabih

Discussion: https://postgr.es/m/alpine.DEB.2.20.1610031049310.19411@lancre

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/cdc2a70470bdbe3663dc464deb753d6d931bba61

Modified Files
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doc/src/sgml/ref/pgbench.sgml | 6 ++++--
src/bin/pgbench/exprscan.l | 21 +++++++++++++++++++--
2 files changed, 23 insertions(+), 4 deletions(-)