Support lifetimebound calls where return type is not a pointer/view type

[usx95]

#include <iostream>
#include <string>
#include <string_view>

struct S {
    std::string_view data;
};

S getS(const std::string& s [[clang::lifetimebound]]) { return S{s}; }

void foo() {
    S s;
    {
        std::string str = "small scoped string";
        s = getS(str);
    }
    std::cout << s.data; // use-after-free
}

https://godbolt.org/z/9s1xqc3nW

[llvmbot]

@llvm/issue-subscribers-clang-temporal-safety

Author: Utkarsh Saxena (usx95)

```cpp #include <iostream> #include <string> #include <string_view>

struct S {
std::string_view data;
};

S getS(const std::string& s [[clang::lifetimebound]]) { return S{s}; }

void foo() {
S s;
{
std::string str = "small scoped string";
s = getS(str);
}
std::cout << s.data; // use-after-free
}

https://godbolt.org/z/9s1xqc3nW
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