[x265] ASM crash in r6706

[Jason Garrett-Glaser]

>>x86inc handles this already when it references values in the stack.
>>If it didn't, none of x264's asm would function.
>>
> yes, for value only
> it didn't align stack for reserve stack space (4th parameters of cglobal)

If it doesn't, that has nothing to do with registers it's pushed on
the stack -- that means that x264asm got a misaligned stack passed to
it in the first place, but wasn't told to assume incoming stacks are
misaligned.

x264asm tracks its own stack_offset when it performs stack operations,
including the allocation of scratch space.

Jason