Make stdlib extensions backwards compatible (#512)

Author: vchuravy

Project.toml

@@ -8,9 +8,11 @@ Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"
 Atomix = "a9b6321e-bd34-4604-b9c9-b65b8de01458"
 EnzymeCore = "f151be2c-9106-41f4-ab19-57ee4f262869"
 InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MacroTools = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"
 PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 Requires = "ae029012-a4dd-5104-9daa-d747884805df"
+SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 UUIDs = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
 UnsafeAtomics = "013be700-e6cd-48c3-b4a1-df204f14c38f"

ext/LinearAlgebraExt.jl

@@ -1,11 +1,7 @@
 module LinearAlgebraExt
 
 using KernelAbstractions: KernelAbstractions
-if isdefined(Base, :get_extension)
-    using LinearAlgebra: Tridiagonal, Diagonal
-else
-    using ..LinearAlgebra: Tridiagonal, Diagonal
-end
+using LinearAlgebra: Tridiagonal, Diagonal
 
 KernelAbstractions.get_backend(A::Diagonal) = KernelAbstractions.get_backend(A.diag)
 KernelAbstractions.get_backend(A::Tridiagonal) = KernelAbstractions.get_backend(A.d)

ext/SparseArraysExt.jl

@@ -1,11 +1,7 @@
 module SparseArraysExt
 
 using KernelAbstractions: KernelAbstractions
-if isdefined(Base, :get_extension)
-    using SparseArrays: AbstractSparseArray, rowvals
-else
-    using ..SparseArrays: AbstractSparseArray, rowvals
-end
+using SparseArrays: AbstractSparseArray, rowvals
 
 function KernelAbstractions.get_backend(A::AbstractSparseArray)
     return KernelAbstractions.get_backend(rowvals(A))

src/KernelAbstractions.jl

@@ -769,4 +769,9 @@ end
     end
 end
 
+if !isdefined(Base, :get_extension)
+    include("../ext/LinearAlgebraExt.jl")
+    include("../ext/SparseArraysExt.jl")
+end
+
 end #module