[clang-tidy] "bugprone-return-const-ref-from-parameter" - should consider `*this` as a parameter

[denzor200]

As I suppose this check is expected to show warning in A::getThis method:

struct A {
  const A& getThis() const{ return *this; };
};

But it didn't. Logically I don't see any difference between A::getThis method and getThis regular function like this:

const A& getThis(const A& a) { return a; };

But the alalizer thinks that there is a difference! And show warning only for getThis regular function.
The warning should also be provided for A::getThis method because the known lifetime issue is also actual for it:

const auto& a = A().getThis();
// dangling `a`

The full snippet here: https://godbolt.org/z/xb669s6f3

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: Denis Mikhailov (denzor200)

As I suppose this check is expected to show warning in `A::getThis` method: ``` struct A { const A& getThis() const{ return *this; }; }; ``` But it didn't. Logically I don't see any difference between `A::getThis` method and `getThis` regular function like this: ``` const A& getThis(const A& a) { return a; }; ``` But the alalizer thinks that there is a difference! And show warning only for `getThis` regular function. The warning should also be provided for `A::getThis` method because the known lifetime issue is also actual for it: ``` const auto& a = A().getThis(); // dangling `a` ```

The full snippet here: https://godbolt.org/z/xb669s6f3