[llvm] [RemoveDIs] Load into new debug info format by default in llvm-reduce (PR #86275)

[Stephen Tozer via llvm-commits]

SLTozer wrote:

Do we want this to happen in llvm-reduce? Until the old debug info format is removed, we would probably want llvm-reduce to maintain whatever format the file is in - otherwise if, for example, we encountered a bug that only occurred for bitcode/IR files that were written with the old format, we would be unable to use llvm-reduce to get a reduced reproducer from the input.

https://github.com/llvm/llvm-project/pull/86275