let homogeneous tuples be alldense (#445)

* let homogeneous tuples be `alldense`

This lets LoopVectorization work more broadly .. e.g. VectorizedStatistics can process NTuples, `vminimum((1.0,2.0,0.5,1.5))` (currently it chokes).

* Update src/simdfunctionals/map.jl

Co-authored-by: Chris Elrod <[email protected]>

Author: JeffreySarnoff

src/simdfunctionals/map.jl

@@ -266,6 +266,7 @@ end
 @inline _all_dense(t::Tuple{ArrayInterface.True,ArrayInterface.False,Vararg}) = false
 @inline _all_dense(t::Tuple{ArrayInterface.False,Vararg}) = false
 @inline all_dense() = true
+@inline all_dense(t::NTuple{N}) where {N} = true
 @inline all_dense(A::Array) = true
 @inline all_dense(A::AbstractArray) = _all_dense(ArrayInterface.dense_dims(A))
 @inline all_dense(