Backport patch by David Barker converting arguments to pointers.
The win32 ABI spills to the stack after the first three arguments,
but doesn't guarantee correct alignment for simd data there.
This is fixed upstream, but I don't want to bump our commit
just yet since it forces a re-encode of active demo streams.
Patch from https://bugs.chromium.org/p/aomedia/issues/detail?id=587
MozReview-Commit-ID: 1pQaU8H1dXO
--HG--
extra : rebase_source : 2ff412e5b44fcf29ac794fc889a37158ab14bc61
