Zig's New BitCast Semantics and LLVM Back End Improvements

Zig has introduced pointer stability locks to its standard library's ArrayList container, a safety feature previously added to HashMap in 2024. This mechanism requires developers to call `lockPointers()` and `unlockPointers()` when storing pointers to ArrayList elements, preventing crashes caused by memory reallocation that invalidates those pointers. The feature provides clear panic messages with stack traces when pointer stability assumptions are violated, making memory bugs easier to debug.