For some reason I had convinced myself that functions returning by pointer or reference do not require recording their result. However, after further considering I don't see how that could work, at least not with the current implementation. Interestingly enough, the reproducer instrumentation already (mostly) accounts for this, though the lldb-instr tool did not.
This patch adds the missing macros and updates the lldb-instr tool.
Let's cast this or hide it behind a macro to prevent code duplication.