This test was overfitting what it was trying to test, causing different
targets (and even different assert configurations) to fail to match.
Instead, make this an executable test and ensure that round-tripping
through setting and getting behaves as expected.
Fixes rdar://46486517
...and remove the option. This is ~technically~ CLI-breaking because
Swift 5 shipped this as a hidden driver option, but it wouldn't have
/done/ anything in Swift 5, so I think it's okay to remove.
Note that if a parseable interface (.swiftinterface) and a binary
interface (.swiftmodule) are both present, the binary one will still
be preferred. This just /allows/ parseable interfaces to be used.
rdar://problem/36885834
Instead of only printing through the pattern binding, and potentially missing stored properties with property observers, defer to the pattern binding for all stored properties, and print accessors if applicable while printing pattern bindings.
