Use GenericArray instead of adjoint to ensure fallback method is hit

Author: jishnub

test/triangular.jl

@@ -6,6 +6,7 @@ isdefined(Main, :pruned_old_LA) || @eval Main include("prune_old_LA.jl")
 
 using Test, LinearAlgebra, Random
 using LinearAlgebra: errorbounds, transpose!, BandIndex
+using Test: GenericArray
 
 const BASE_TEST_PATH = joinpath(Sys.BINDIR, "..", "share", "julia", "test")
 
@@ -655,8 +656,8 @@ end
         for T in (UnitUpperTriangular, UnitLowerTriangular)
             isupper = T == UnitUpperTriangular
             M = Matrix{BigFloat}(undef, 2, 2)
-            M[1+isupper,1+!isupper] = 3
-            U = T(M')
+            M[1+!isupper,1+isupper] = 3
+            U = T(GenericArray(M))
             @test copyto!(similar(M), U) == U
         end
     end