Fix a compiler crash with '@'_lifetime(inout x), add diagnostic
This is a common mistake made more common be suggestions of existing diagnostic
that tell users not to use a 'copy' dependency.
Report a diagnostic error rather than crashing the compiler. Fix the diagnostic
output to make sense relative to the source location.
Fixes rdar://154136015 ([nonescapable] compiler assertion with @_lifetime(x: inout x))