[CodeComplete] Fix crasher when completing inout IUO variable

[rintaro]

func test(arg: inout Int!) {
   <COMPLETE>
}

Here, type of arg is

(inout_type
  (optional_type
    (struct_type decl=Swift.(file).Int)))

Previously, it's assumed that the type was OptionalType. That used to fail getOptionalObjectType(). Instead, use PrintOptionalAsImplicitlyUnwrapped option that prints ! for outer most optional type.

rdar://problem/40956846

[rintaro]

@swift-ci Please smoke test

[rudkx]

Can you add a test case with an inout IUO that requires parens to be printed around the underlying object type for it to display correctly?

For example func test(_ fn: ((Int)->Int)!) { }

[rintaro]

@rudkx I already have a test case for (() -> Int)!.

[rudkx]

Oh I didn't paste in the right example - I meant an inout variant of that, like inout (() -> Int)!.

[rudkx]

LGTM, but it would be nice to have another test that is inout that requires the underlying type to have parentheses.

[rintaro]

Thank you! Added a test case.
@swift-ci Please smoke test