Add `lifetimebound` to ArrayRef and StringRef to detect dangling issues

[hokein]

Adding the lifetimebound annotation to the ArrayRef's array constructor can enable us to detect the following use-after-free issues:

ArrayRef<int> test() {
   int array[10];
   return array; // bug, return a stack local address
}

cc @Xazax-hun, @usx95

[Xazax-hun]

Probably people run into that less frequently, but we could annotate all containers in ADT including small vector and such. They have a number of APIs handing out pointers and references that have the same lifetime as the container itself.

[hokein]

Probably people run into that less frequently, but we could annotate all containers in ADT including small vector and such. They have a number of APIs handing out pointers and references that have the same lifetime as the container itself.

Thanks for the idea, annotating all containers in ADT could certainly help.

My intention of this issue primarily targets the ArrayRef and StringRef constructors, which have already discovered some bugs in our internal codebase.

[hokein]

Closing this issue now, as annotations for both ArrayRef and StringRef have been added.