pgsql: Recognize that MSVC can support strtoll() and strtoull().

Recognize that MSVC can support strtoll() and strtoull().

This is needed for full support of "long long" variables in ecpg, but
the previous patch for bug #15080 (commits 51057feaa et al) missed it.
In MSVC versions where the functions don't exist under those names,
we can nonetheless use _strtoi64() and _strtoui64().

Like the previous patch, back-patch all the way.

Dang Minh Huong

Discussion: https://postgr.es/m/151935568942.1461.14623890240535309745@wrigleys.postgresql.org

Branch
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REL9_4_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/385f4acbf824f520287f20373ebae4713382a568

Modified Files
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src/include/pg_config.h.win32 | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)