Added tests for PSparseMatrix copyto!

Author: JordiManyer

test/p_sparse_matrix_tests.jl

@@ -63,6 +63,7 @@ function p_sparse_matrix_tests(distribute)
     _A = similar(A)
     _A = similar(A,eltype(A),axes(A))
     #_A = similar(typeof(A),axes(A)) # This should work, but fails down the line in SparseArrays.jl
+    copy!(_A,A)
 
     LinearAlgebra.fillstored!(A,1.0)
     fill!(x,3.0)