While adding the `@throws` documentation to the code in #600 I realized there is nonly a single function in the interface which is throwing explicitly (`simplecp::characterLiteralToLL()`). We should probably be consistent and make this function non-throwing as well. To enforce that the interface does not throw we should also try to mark functions as `noexcept`. But we should wait with this until there's a tool-driven way to validate this (i.e. https://github.com/llvm/llvm-project/pull/168324).