fix jacobi inconsistence and use more stable testdata

1. diagonal invert was one in reference but zero in other backend
2. nvhpc 23.3 may optimize the formula in different way for scaled_value in make_diag_dominant, which lead the updated value is slightly different

Author: yhmtsai

common/unified/preconditioner/jacobi_kernels.cpp

@@ -42,7 +42,8 @@ void invert_diagonal(std::shared_ptr<const DefaultExecutor> exec,
     run_kernel(
         exec,
         [] GKO_KERNEL(auto elem, auto diag, auto inv_diag) {
-            inv_diag[elem] = safe_divide(one(diag[elem]), diag[elem]);
+            inv_diag[elem] = is_zero(diag[elem]) ? one(diag[elem])
+                                                 : one(diag[elem]) / diag[elem];
         },
         diag.get_size(), diag, inv_diag);
 }

test/preconditioner/jacobi_kernels.cpp

@@ -515,7 +515,7 @@ TEST_F(Jacobi, ScalarL1ApplyEquivalentToRef)
         gko::test::generate_random_matrix_data<value_type, index_type>(
             dim, dim, std::uniform_int_distribution<>(1, dim),
             std::normal_distribution<>(1.0, 2.0), engine);
-    gko::utils::make_diag_dominant(dense_data);
+    gko::utils::make_diag_dominant(dense_data, 1.001);
     auto dense_smtx = gko::share(Vec::create(ref));
     dense_smtx->read(dense_data);
     auto smtx = gko::share(Mtx::create(ref));