Merge pull request JuliaCollections#907 from Tortar/patch-1

Improve performance of sizehint! on BinaryHeap

src/heaps/arrays_as_heaps.jl

@@ -75,7 +75,7 @@ end
 
 In-place [`heapify`](@ref).
 """
-function heapify!(xs::AbstractArray, o::Ordering=Forward)
+@inline function heapify!(xs::AbstractArray, o::Ordering=Forward)
     for i in heapparent(length(xs)):-1:1
         percolate_down!(xs, i, o)
     end