Issue Description:

Hi Apple,

There seems to be a minor oversight in the current implementation of SE-0274 — Concise Magic File Names. It is still possible to have the user's full path encoded in application binaries if they use the force operator '!' as the path is included in the diagnostic message. For example, force unwraps or force casts:
```
var a: String?
print(a as! String)
fatalError("Eh?")
```
```
$ strings b
/tmp/a.swift
Unexpectedly found nil while unwrapping an Optional value
Fatal error
a.swift (b)
_TtCs12_SwiftObject
__TEXT
swift_getObjCClassMetadata
__swift5_proto
```
Implicit capture of #file in functions such as fatalError seems to be fine.