pgsql: Add #define INT64_MODIFIER for the printf length modifier for 64

Add #define INT64_MODIFIER for the printf length modifier for 64-bit ints.

We have had INT64_FORMAT and UINT64_FORMAT for a long time, but that's not
good enough if you want something more exotic, like "%20lld".

Abhijit Menon-Sen, per Andres Freund's suggestion.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/ce486056ecd28050f367894a2b5aad3656d37511

Modified Files
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config/c-library.m4           |   32 +++++++++++++++---------------
configure                     |   44 +++++++++++++++++------------------------
configure.in                  |   21 ++++++++------------
src/include/c.h               |    3 +++
src/include/pg_config.h.in    |    7 ++-----
src/include/pg_config.h.win32 |    8 ++------
6 files changed, 49 insertions(+), 66 deletions(-)