implement checks for tail calls
Quoting the [RFC draft](https://github.com/phi-go/rfcs/blob/guaranteed-tco/text/0000-explicit-tail-calls.md):
> The argument to become is a function (or method) call, that exactly matches the function signature and calling convention of the callee. The intent is to ensure a matching ABI. Note that lifetimes may differ as long as they pass borrow checking, see [below](https://github.com/phi-go/rfcs/blob/guaranteed-tco/text/0000-explicit-tail-calls.md#return-type-coercion) for specifics on the return type.
> Tail calling closures and tail calling from closures is not allowed. This is due to the high implementation effort, see below, this restriction can be lifted by a future RFC.
> Invocations of operators were considered as valid targets but were rejected on grounds of being too error-prone. In any case, these can still be called as methods.
> Tail calling [variadic functions](https://doc.rust-lang.org/beta/unstable-book/language-features/c-variadic.html) and tail calling from variadic functions is not allowed. As support for variadic function is stabilized on a per target level, support for tail-calls regarding variadic functions would need to follow a similar approach. To avoid this complexity and to minimize implementation effort for backends, this interaction is currently not allowed but support can be added with a future RFC.
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The checks are implemented as a query, similarly to `check_unsafety`.
The code is cherry-picked straight out of #112657 which was written more than a year ago, so I expect we might need to change some things ^^"
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