[SR-13311] ObjectIdentifier needs documentation that it doesn't retain the object

[swift-ci]

Previous ID	SR-13311
Radar	None
Original Reporter	jaspa (JIRA User)
Type	Bug

Environment

Apple Swift version 5.2.4 (swiftlang-1103.0.32.9 clang-1103.0.32.53)
{{ Target: x86_64-apple-darwin19.5.0}}

Additional Detail from JIRA

Votes	0
Component/s	Standard Library
Labels	Bug, Documentation
Assignee	None
Priority	Medium

md5: 53386ab016ffccd3a8a9240af485690d

Issue Description:

The output of the following code

class C {
  deinit {
    print("object dies")
  }
}

withExtendedLifetime(ObjectIdentifier(C())) {
  print("object identifier lives")
}

is

object dies
object identifier lives

ObjectIdentifier needs documentation that it doesn't retain the identified object.