-Wdangling-gsl only warns on initialization and not on assignment

[Weverything]

Bugzilla Link	47640
Version	trunk
OS	Linux
CC	@dwblaikie,@gribozavr,@mgehre,@zygoloid,@Xazax-hun

Extended Description

-Wdangling-gsl is a warning that catches dangling pointers. This warning catches a lot of lifetime bugs, but it only does so during initialization. Similar code that causes a dangling pointer during assignments does not get a warning.

#include
#include <string_view>
#include

std::string get_string();
std::unique_ptr get_int();

int main() {
std::string_view sv = get_string(); // Warning on initialization
sv = get_string(); // No warning on assignment

int *p = get_int().get(); // Warning on initialization
p = get_int().get(); // No warning on assignment
}

[usx95]

Duplicate #63310 is fixed now.