Instead of four pairs of :1 :15 bit fields, use an array of four :1, :15 structs. This allows to replace the case folding traits classes with a simple enum that indexes into said array. I don't know what the WASM #ifdef'ed code is supposed to effect (a :0 bit-field is only useful to separate adjacent bit-field into separate memory locations for multi-threading), but I thought it safer to leave it in, and that means the array must be a 64-bit block of its own, so I had to move two fields around. Saves ~4.5KiB in text size on optimized GCC 10 LTO Linux AMD64 builds. Change-Id: Ib52cd7706342d5227b50b57545d073829c45da9a Reviewed-by: Lars Knoll <lars.knoll@qt.io>