While armv7 generally tolerates unaligned loads/stores in most
cases, the compiler is free to use the ldrd/strd instructions,
for loading/storing two consecutive 32 bit registers, and this
requires the destination to be aligned to a 4 byte boundary.

When packing a number of variable length structures, make sure
that each actual struct gets aligned at the right address
boundary.

This fixes crashes in DllMain of wineps.drv, when built for
armv7, since 351e58dc.
Signed-off-by: Martin Storsjö <martin@martin.st>