[llvm] [RISCV] Add compress patterns for Xqcibi branch instructions (PR #143095)

[Sam Elliott via llvm-commits]

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lenary wrote:

Thanks for updating the existing tests, can you also add a few examples with e.g. `qc.e.beqi a0, 0xa, .Ln` to show that it gets turned into `qc.beqi a0, 0xa, 0x8; jal zero, ...` (i.e. that the `qc.e.beqi` first gets compressed to the form with a smaller immediate, and then relaxed to the branch;jump variant)

https://github.com/llvm/llvm-project/pull/143095