[pstl] Use logical operator for loop condition in tests

[jwakely]

Summary

Fix a probable typo in two PSTL tests that causes warnings with GCC.

[zoecarver]

This is a nfc and obviously correct, so feel free to land it. Do you have commit access? If not I'm happy to commit.

[jwakely]

No, I don't have commit access, so that would be great. Thanks, Zoe.

pstl/test/std/algorithms/alg.nonmodifying/find_end.pass.cpp

test(const std::size_t bits)
     {
         std::size_t sub_n[] = {0, 1, 3, n1, (n1 * 10) / 8};
         std::size_t res[] = {0, 1, n1 / 2, n1};
         for (auto n2 : sub_n)
         {
             for (auto r : res)
             {
                 std::size_t i = r, isub = 0;
-                for (; i < n1 & isub < n2; ++i, ++isub)
+                for (; i < n1 && isub < n2; ++i, ++isub)
                     in[i] = sub[isub];
                 invoke_on_all_policies(test_one_policy(), in.begin(), in.begin() + n1, sub.begin(), sub.begin() + n2,
                                        std::equal_to<T>());
                 invoke_on_all_policies(test_one_policy(), in.cbegin(), in.cbegin() + n1, sub.cbegin(),
                                        sub.cbegin() + n2, std::equal_to<T>());
             }
         }
     }

pstl/test/std/algorithms/alg.nonmodifying/search_n.pass.cpp

for (std::size_t n1 = 0; n1 <= max_n1; n1 = n1 <= 16 ? n1 + 1 : size_t(3.1415 * n1))
             if (n2 == 0)
             {
                 continue;
             }
             for (auto r : res)
             {
                 Sequence<T> in(n1, [](std::size_t) { return T(0); });
                 std::size_t i = r, isub = 0;
-                for (; i < n1 & isub < n2; ++i, ++isub)
+                for (; i < n1 && isub < n2; ++i, ++isub)
                     in[i] = value;
 
                 invoke_on_all_policies(test_one_policy(), in.begin(), in.begin() + n1, n2, value, std::equal_to<T>());
                 invoke_on_all_policies(test_one_policy(), in.cbegin(), in.cbegin() + n1, n2, value, std::equal_to<T>());
             }
         }
     }
 }