[clang] [clang-format] unexpected break after binOp '<<' (PR #69859)

[Owen Pan via cfe-commits]

owenca wrote:

> 2th solution is: Add new option that allowing specific behaviour, such as "BreakAfterStreamOperator" or "BreakAfterLessLessOperator" with options [ Leave | NoFitLine | All ].

We need a comprehensive solution to cover the following:
- when to break
- before or after the operator
- indenting or aligning
- binpack or one per line
- whether to break after a newline (`\n`, `endl`, etc.)

https://github.com/llvm/llvm-project/pull/69859