[llvm-lto2] Added version command for llvm-lto2

[fnriv]

Previously, the only way to check version for llvm-lto2 was to add version as a subcommand: llvm-lto2 run --version. This adds version as a main command for llvm-lto2 for more intuitive access.

You can now check version with the command llvm-lto2 --version.

[github-actions]

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