pgsql: Get still more info about Windows can't-reattach-to-shared-memor

Get still more info about Windows can't-reattach-to-shared-memory errors.

After some thought about the info captured so far, it seems possible
that MapViewOfFileEx is itself causing some DLL to get loaded into
the space just freed by VirtualFree. The previous commit here didn't
capture enough info to really prove the case for that, so let's add
one more VirtualQuery in between those steps. Also, be sure to
capture the post-Map state before we emit any log entries, just in
case elog() is invoking some code not previously loaded.

Discussion: https://postgr.es/m/25495.1524517820@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/eb16011f4c08a8c2ddfbf0637b862ee1918dd9b2

Modified Files
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src/backend/port/win32_shmem.c | 43 ++++++++++++++++++++++++++++++++----------
1 file changed, 33 insertions(+), 10 deletions(-)