Test improvement follow-up (#387)

* Also gitignore version-specific manifests

* Run tests when not default backend but still supported

Author: christiangnrd

.gitignore

@@ -1 +1,2 @@
 Manifest.toml
+Manifest-*.toml

test/array.jl

@@ -49,7 +49,7 @@ import Adapt
     end
     # TODO: Look into how to port the @sync
 
-    if cl.memory_backend() isa cl.USMBackend
+    if cl.USMBackend() in cl.supported_memory_backends(cl.device())
         @testset "shared buffers & unsafe_wrap" begin
             a = CLVector{Int, cl.UnifiedSharedMemory}(undef, 2)
 

test/buffer.jl

@@ -74,7 +74,7 @@
     end
 end
 
-if cl.memory_backend() isa cl.SVMBackend
+if cl.SVMBackend() in cl.supported_memory_backends(cl.device())
 @testset "SVM Buffer" begin
     # simple buffer
     let buf = cl.svm_alloc(sizeof(Int))