Define Base.dataids method for FixedSizeArrays (#64)

Co-authored-by: Neven Sajko <s@purelymail.com>

Author: giordano

src/FixedSizeArrays.jl

@@ -392,4 +392,11 @@ function collect_as(::Type{T}, iterator) where {T<:FixedSizeArray}
     collect_as_fsa_checked(iterator, spec, dim_count, len_stat)::T
 end
 
+if isdefined(Base, :dataids) && (Base.dataids isa Function)
+    # This is an internal, non-public function which is nevertheless needed to
+    # get good performance in some cases (e.g. broadcasting):
+    # <https://github.com/JuliaArrays/FixedSizeArrays.jl/issues/63>.
+    Base.dataids(a::FixedSizeArray) = Base.dataids(a.mem)
+end
+
 end # module FixedSizeArrays