Lint idea: warn about implicit drop

When writing low level code it is sometimes desirable to not have implicit drop calls.

For instance when interfacing with Lua one often has Rust function called by Lua, which in turn call Lua functions. One can execute a Lua function using lua_call. Errors in the Lua code are handled using longjmp, which can jump to a handler in the original Lua caller thus skipping the Execution of the rest of the Rust function.
In such a situation one wants to make sure no code is executed implicitly after lua_call (because it might be skipped).
Ideally this lint can be enabled both for single values that should not be dropped implicitly as well as functions in which nothing should be dropped implicitly

The issue names no files, tests, or entry points. Begin by defining the intended lint scope for individual values and functions, then establish how implicit drops should be detected and what tests would demonstrate that execution after lua_call is not silently skipped.