[clang] [clang-format] Add ShortReturnTypeLength option. (PR #78011)

[Björn Schäpers via cfe-commits]

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@@ -3928,6 +3928,13 @@ struct FormatStyle {
   /// \version 13
   unsigned ShortNamespaceLines;
 
+  /// When AlwaysBreakAfterReturnType is None, line breaks are prevented after
+  /// short return types. This configures the character limit for a type to be
+  /// regarded as short. Note that this isn't the length of the type itself,
+  /// but the column where it finishes. I.e. it includes indentation, etc.
+  /// \version 18
+  unsigned ShortReturnTypeLength;
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HazardyKnusperkeks wrote:

```suggestion
  unsigned ShortReturnTypeColumn;
```
As stated in your note, this is clearer. And for a note we have `\note`.

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