Remove trailing newline from iree-run-mlir split-input-file marker
Remove trailing newline from iree-run-mlir split-input-file marker

This matches the behavior of mlir-translate and mlir-opt libraries. It means that extra dashes will probably cause a parse error instead of silently not splitting, which...I guess is better? But at least I think it's better if these are consistent. I tried out using the shared translate/opt tool utility for doing this (https://github.com/llvm/llvm-project/blob/master/mlir/lib/Support/ToolUtilities.cpp), but there ended up being so much grossness trying to join up the LLVM and ABSL APIs and logging that I stopped. We should maybe revisit this at a later point as part of a larger cleanup of iree-run-mlir.

PiperOrigin-RevId: 291851046

iree-org/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,google/iree