Add new memory management functions for reallocations and etc.

[aleasims]

This is an umbrella issue for expanding zkLLVM set of memory management functions to complete.

Right now we have only malloc and free. This is not enough to handle even growable vectors in both C++ and Rust. We need to support full set of memory management functions in our compilers and assigner.

Tasks:

• [ ] NilFoundation/zkllvm-circifier/issues/96
• [ ] NilFoundation/zkllvm-rslang/issues/75
• [ ] NilFoundation/zkllvm-stdlib/issues/13
• [ ] NilFoundation/zkllvm-assigner/issues/166
• [ ] Add examples which use these function (in Rust and C++)