[clang] [polly] [clang-format] Add AllowShortType and ExceptShortType options for AlwaysBreakAfterReturnType. (PR #78011)

[Owen Pan via cfe-commits]

================
@@ -922,8 +922,39 @@ struct FormatStyle {
     ///   };
     ///   int f();
     ///   int f() { return 1; }
+    ///   int LongName::
+    ///       AnotherLongName();
     /// \endcode
     RTBS_None,
+    /// Break after return type automatically.
+    /// This mode doesn't have the same inherent restriction on breaking after
+    /// short return types as ``RTBS_None`` and is solely based on
+    /// ``PenaltyReturnTypeOnItsOwnLine``.
----------------
owenca wrote:

For example:
```suggestion
    /// Break after return type based on ``PenaltyReturnTypeOnItsOwnLine``.
```

https://github.com/llvm/llvm-project/pull/78011