[clang] [analyzer] Add alpha.cplusplus.BoundsInformation checker (PR #112784)

[Artem Dergachev via cfe-commits]

haoNoQ wrote:

> a function that returns a pointer and takes a reference (or a pointer) to a length variable

Yes, this one should be easy to catch. Both values will be `SymbolConjured` pointing to the same function call expression / program point. (The out-parameter value may also be `SymbolDerived` which is derived from the same `SymbolConjured`; you may need to carefully unwrap it, as well as make sure that it's not falling into the "known origin region" category because `SymbolDerived` does indeed respond nicely to `->getOriginRegion()`).

https://github.com/llvm/llvm-project/pull/112784