old_contents: """List of special Go suffixes."""
  
  go_suffixes = [
      "_386",
      "_386_unsafe",
      "_aarch64",
      "_aarch64_unsafe",
      "_amd64",
      "_amd64_unsafe",
      "_arm",
      "_arm64",
      "_arm64_unsafe",
      "_arm_unsafe",
      "_impl",
      "_impl_unsafe",
      "_linux",
      "_linux_unsafe",
      "_mips",
      "_mips64",
      "_mips64_unsafe",
      "_mips64le",
      "_mips64le_unsafe",
      "_mips_unsafe",
      "_mipsle",
      "_mipsle_unsafe",
      "_opts",
      "_opts_unsafe",
      "_ppc64",
      "_ppc64_unsafe",
      "_ppc64le",
      "_ppc64le_unsafe",
      "_riscv64",
      "_riscv64_unsafe",
      "_s390x",
      "_s390x_unsafe",
      "_sparc64",
      "_sparc64_unsafe",
      "_wasm",
      "_wasm_unsafe",
  ]
  
new_contents: """List of special Go suffixes."""
  
  def explode(tagset, suffixes):
      """explode combines tagset and suffixes in all ways.
  
      Args:
        tagset: Original suffixes.
        suffixes: Suffixes to combine before and after.
  
      Returns:
        The set of possible combinations.
      """
      result = [t for t in tagset]
      result += [s for s in suffixes]
      for t in tagset:
          result += [t + s for s in suffixes]
          result += [s + t for s in suffixes]
      return result
  
  archs = [
      "_386",
      "_aarch64",
      "_amd64",
      "_arm",
      "_arm64",
      "_mips",
      "_mips64",
      "_mips64le",
      "_mipsle",
      "_ppc64",
      "_ppc64le",
      "_riscv64",
      "_s390x",
      "_sparc64",
      "_x86",
  ]
  
  oses = [
      "_linux",
  ]
  
  generic = [
      "_impl",
      "_race",
      "_norace",
      "_unsafe",
      "_opts",
  ]
  
  # State explosion? Sure. This is approximately:
  #   len(archs) * (1 + 2 * len(oses) * (1 + 2 * len(generic))
  #
  # This evaluates to 495 at the time of writing. So it's a lot of different
  # combinations, but not so much that it will cause issues. We can probably add
  # quite a few more variants before this becomes a genuine problem.
  go_suffixes = explode(explode(archs, oses), generic)
  
subject: Fix tags used for determining file sets.