GPU issue indexing flat fields

[jagoosw]

When I try to index into a field which has nothing topology in a kernel, e.g.:

@kernel function add_one!(A)
    i, j = @index(Global, NTuple)
    A[i, j] += 1
end

then it works on CPU, but hits a dynamic function invocation on line 82 here:

Oceananigans.jl/src/Grids/grid_utils.jl

Lines 81 to 89 in 2b601f1

	@inline function Base.size(loc, topo, sz, indices=default_indices(Val(length(loc))))
	D = length(loc)
	# (it's type stable?)
	return ntuple(Val(D)) do d
	Base.@_inline_meta
	length(instantiate(loc[d]), instantiate(topo[d]), sz[d], indices[d])
	end
	end

could we rewrite this like:

@inline function Base.size(loc::NTuple{N},...) where N

instead?