py: Add mp_obj_is_float function (macro) and use it where appropriate.
diff --git a/py/objint_mpz.c b/py/objint_mpz.c
index 2255fd6..18e698f 100644
--- a/py/objint_mpz.c
+++ b/py/objint_mpz.c
@@ -178,7 +178,7 @@
     } else if (MP_OBJ_IS_TYPE(rhs_in, &mp_type_int)) {
         zrhs = &((mp_obj_int_t*)rhs_in)->mpz;
 #if MICROPY_PY_BUILTINS_FLOAT
-    } else if (MP_OBJ_IS_TYPE(rhs_in, &mp_type_float)) {
+    } else if (mp_obj_is_float(rhs_in)) {
         return mp_obj_float_binary_op(op, mpz_as_float(zlhs), rhs_in);
 #if MICROPY_PY_BUILTINS_COMPLEX
     } else if (MP_OBJ_IS_TYPE(rhs_in, &mp_type_complex)) {