[Sema] Emit only "public" access modifier in fix-it for missing witness

[rintaro]

protocol P {
   func foo()
}
private class C : P {
}

Previously, fix-it tries to insert internal func foo() { <#code#> }.

With this PR, fix-it emits public access modifier only if the protocol and the class are public (or open).

[rintaro]

@swift-ci Please smoke test

[jrose-apple]

Code LGTM. @benlangmuir?

Can you add a test for a non-type requirement that needs public as well?

[benlangmuir]

LGTM too

[rintaro]

@jrose-apple @benlangmuir Thanks!

@jrose-apple What "non-type requirement" mean? non-class-type?

[jrose-apple]

Non-associated-type. Right now the only test that inserts "public" is the associated type one, right? Or are there some that just didn't show up in the diff because they didn't change?

[rintaro]

@jrose-apple Here's non-associatedtype test that emits public. Do we need init(), var, or subscript too?

[jrose-apple]

Oh, I'm sorry, somehow I missed this one. All good, please feel free to merge.

[rintaro]

:)
Sorry, I'm not authorized to merge. Could you?

Or @shahmishal, Could you authorize me to merge?

[benlangmuir]

Instructions for getting commit access are at https://swift.org/contributing/#contributing-code "Commit Access" 😃

[rintaro]

@benlangmuir Thanks!

Actually I've been granted commit access on Jun. 1.
IIRC, from around Jul. 27, it seems only Apple members can merge into the master.
We non-apple "granted" contributors can trigger CI, but can't push Github "Merge pull request" buttons on this repo.
@modocache or @jtbandes, Could you confirm this?

[modocache]

Yes, I believe that's true. I'm unable to merge my code directly.

[jtbandes]

Same here, at least in this repo. I can merge into swift-evolution.

[benlangmuir]

@shahmishal tells me this should be fixed now. After the required tests have passed, you should be able to hit the merge button if you have commit access. Let us know if it doesn't work!

[rintaro]

Confirmed on other PRs. Thank you!

[jtbandes]

Yes, the merge button is green now. Thanks 😄