crypt32(0/38): Fix some crashes on win64

[Juan Lang]

This patch series attempts to address some of the crashing tests on
Wine in 64-bit mode (see e.g.
http://test.winehq.org/data/e8ce3e600a40a739f75d6716aae555c31b0b4d0d/index_Wine.html#crypt32:message
).  In particular, they remove one invalid assumption: that a pair of
members of a structure, (DWORD, pointer), are aligned adjacent to one
another in memory.
--Juan