unweave: Fix for MSVC 2022 ARM Preview probable compiler bug

See https://stackoverflow.com/questions/78608330/postfix-increment-compiler-bug-on-visual-studio-2022-arm-preview?noredirect=1#comment138587024_78608330

Author: pthom

include/fplus/container_common.hpp

@@ -1278,10 +1278,11 @@ std::pair<Container, Container> unweave(const Container& xs)
     auto it_odd = internal::get_back_inserter<Container>(result.second);
     std::size_t counter = 0;
     for (const auto& x : xs) {
-        if (counter++ % 2 == 0)
+        if (counter % 2 == 0)
             *it_even = x;
         else
             *it_odd = x;
+        counter++;
     }
     return result;
 }

include_all_in_one/include/fplus/fplus.hpp

@@ -4373,10 +4373,11 @@ std::pair<Container, Container> unweave(const Container& xs)
     auto it_odd = internal::get_back_inserter<Container>(result.second);
     std::size_t counter = 0;
     for (const auto& x : xs) {
-        if (counter++ % 2 == 0)
+        if (counter % 2 == 0)
             *it_even = x;
         else
             *it_odd = x;
+        counter++;
     }
     return result;
 }