[clang][Sema] Warn on return of pointer/reference to compound literal (#83741)

Emit a warning if pointer/reference to compound literal is returned from
a function.

In C, compound literals in block scope are lvalues that have automatic
storage duration. In C++, compound literals in block scope are
temporaries.

In either case, returning a pointer/reference to a compound literal can
cause a use-after-free bug.

Fixes #8678