Store node integers by halves on big-endian targets

The non-little-endian path of the node writer wrote the integer's native
word over len and next, so len got the high half there. Compose and split
the value explicitly (len is the low half, next the high half); the
little-endian path stays a plain memcpy.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

include/nlohmann/detail/view/builder.hpp

@@ -801,7 +801,10 @@ indent_done:
             n->flags = flags;
             n->extra = extra;
             n->off = static_cast<std::uint32_t>(off);
-            set_integer_bits(*n, second);
+            // len is the low half of the second word, next the high half
+            // (not a native word over both, which swaps them on big-endian)
+            n->len = static_cast<std::uint32_t>(second);
+            n->next = static_cast<std::uint32_t>(second >> 32);
 #endif
             return n;
         }