Update llvm-libunwind to 22.1.1

[am11]

Update step (first commit):

$ LLVM_VER=22.1.0
$ DEST=src/native/external/llvm-libunwind
$ rm -rf $DEST && mkdir $DEST
$ curl -sSL https://github.com/llvm/llvm-project/archive/refs/tags/llvmorg-$LLVM_VER.tar.gz |
    tar -C $DEST --strip-components=2 -xz -f - llvm-project-llvmorg-$LLVM_VER/libunwind

Second commit cherry-picks old patches commit and third commit reference second commit in versions file.

Important

This PR should be merged without squashing to keep commit references.

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[am11]

@mthalman, we could set up Renovate or train Copilot to handle this automatically alongside PRs like dotnet/dotnet-buildtools-prereqs-docker#1614. It’s not strictly required to keep llvm-libunwind in sync with the toolchain, but it’s good hygiene and helps prevent it from being overlooked. The second and third commit interlinked reference thing (see PR description) is a bit tricky but AI can figure it out by looking at this series of PRs (previous update: #113513). 🙂

[jkotas]

/azp run runtime-nativeaot-outerloop