The gc.statepoint intrinsic expects two i32's after the function argument, not i64's.
I'll note that the requirement that the # call args and flags are i32s conflicts with the rest of the documentation, namely, that the flags argument is 64 bits wide.
Is the documentation about the flags argument being an i64 also wrong, or is the intrinsic type checker wrong?
Well, at least one of them is wrong. :) I'd go with changing the doc to avoid breaking out of tree users (since, clearly, they could not have been using a 64 bit flag "according to spec").