[clang] [ASTContext] Add a break to nested switch in `encodeTypeForFunctionPointerAuth` (PR #99763)

[Brandon Wu via cfe-commits]

================
@@ -3363,6 +3363,7 @@ static void encodeTypeForFunctionPointerAuth(const ASTContext &Ctx,
 #include "clang/Basic/RISCVVTypes.def"
       llvm_unreachable("not yet implemented");
     }
+    break;
----------------
4vtomat wrote:

Do you mean we should allow it to work if someone adds a new enum but doesn't update the code?
That's why I added a break rather than unreachable haha~
btw, why we get an error if having `default` case on a fully covered switch?


https://github.com/llvm/llvm-project/pull/99763