[clang] [clang][Interp] Implement dynamic memory allocation handling (PR #70306)

[Timm Baeder via cfe-commits]

tbaederr wrote:

Thanks for all the help with this issue. I think I figured it out - there was an unsigned wraparound some time before doing the actual allocation, which caused us to write over the bounds of the allocation. I've pushed https://github.com/llvm/llvm-project/commit/72b3d7bc87019ba7ef268ce322f90382f01b11af to ensure this doesn't happen and https://github.com/llvm/llvm-project/commit/e94e72a0c2293a02ea6c5335ac5fbc2d34de13f1 to implement the dynamic allocation management.

https://github.com/llvm/llvm-project/pull/70306