BUG #15080: ecpg on windows doesn't define HAVE_LONG_LONG_INT

The following bug has been logged on the website:

Bug reference:      15080
Logged by:          jonathan allen
Email address:      jallen@americansavingslife.com
PostgreSQL version: 10.2
Operating system:   Windows 10 x64
Description:

I'm trying to access a bigint column on windows using ecpg and I get the
following error:

SQL error: unsupported type "long long" on line x

I found ecpg_get_data() is the call generating the error, and there's a
block of code being skipped because HAVE_LONG_LONG_INT is not defined.  

I found the following code in pg_config.h and tried adding the 3rd line
(#define HAVE_LONG_LONG_INT 1)...

/* Define to 1 if `long long int' works and is 64 bits. */
#if (_MSC_VER > 1200)
#define HAVE_LONG_LONG_INT_64 1
#define HAVE_LONG_LONG_INT 1
#endif

Then I tried recompiling postgres from source and copying over the new bin,
lib, include and shared directories...but no luck, my program is still
throwing the same error.  I asked on the #postgresql irc channel and
RhodiumToad and xocolatl said that if I reported this as a bug paquier would
see this and he'd be the person to ask about it.  

I'd really like to be able to get a fix going that I can compile and use
myself until a new public release is available - this bug has brought our
postgres migration to a standstill, it's a real show stopper. :(

Thank you for looking into this and hopefully pointing me in the right
direction. :)

-Jonathan