message: quench some warnings on MSVC
diff: @@ -91,10 +91,9 @@ ENOKI_TEST_FLOAT(test06_ellint_1) {
  14.28566868 };
  for (int i=-10; i<=10; ++i)
  - assert((ellint_1(i, T(.9f))[0] - result[i+10]) < 2e-6);
  + assert((ellint_1(scalar_t<T>(i), T(.9f))[0] - result[i+10]) < 2e-6);
  }
  -
  ENOKI_TEST_FLOAT(test07_comp_ellint_1) {
  double result[] = { 1.570796327, 1.574745562, 1.586867847, 1.608048620,
  1.639999866, 1.685750355, 1.750753803, 1.845693998,
  @@ -112,7 +111,7 @@ ENOKI_TEST_FLOAT(test08_ellint_2) {
  7.580388582 };
  for (int i=-10; i<=10; ++i)
  - assert((ellint_2(i, T(.9f))[0] - result[i+10]) < 3e-6);
  + assert((ellint_2(scalar_t<T>(i), T(.9f))[0] - result[i+10]) < 3e-6);
  }
  ENOKI_TEST_FLOAT(test09_comp_ellint_2) {
  