New valgrind warnings in wined3d/arb_program_shader.c

[Stefan Dösinger]

> gcc is perfectly correct, if you don't want padding space then your
> bitfields have to add up to the size of an integer.
Figured that out by now :-)

I thought it left paddings between my flags, but actually there are 12 unused bits at the end, and one uninitialized, because unused, but still hashed member adding troubles.