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f879ac0385
Summary: The RPC interface needs to handle an entire warp or wavefront at once. This is currently done by using a compile time constant indicating the size of the buffer, which right now defaults to some value on the client (GPU) side. However, there are currently attempts to move the `libc` library to a single IR build. This is problematic as the size of the wave fronts changes between ISAs on AMDGPU. The builitin `__builtin_amdgcn_wavefrontsize()` will return the appropriate value, but it is only known at runtime now. In order to support this, this patch restructures the packet. Now instead of having an array of arrays, we simply have a large array of buffers and slice it according to the runtime value if we don't know it ahead of time. This also somewhat has the advantage of making the buffer contiguous within a page now that the header has been moved out of it.