http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=mastodon&dt=2009-04-19%2019:00:00
It looks like the MSVC build scripts are cheating by not copying
parser/gram.h into the include tree where it should be. I'm not
entirely sure why that has worked at all in the past, but it's
not working any more.
regards, tom lane