gn analyze output:
{
  "compile_targets": [],
  "status": "No dependency",
  "test_targets": []
}
gn analyze input:
{
  "files": [
    "//utils/bazel/llvm-project-overlay/llvm/BUILD.bazel",
    "//utils/bazel/llvm-project-overlay/mlir/test/BUILD.bazel"
  ],
  "test_targets": [
    "//clang-tools-extra/clangd/test:check-clangd",
    "//clang-tools-extra/test:check-clang-tools",
    "//clang/test:check-clang",
    "//lld/test:check-lld",
    "//llvm/test:check-llvm"
  ],
  "additional_compile_targets": []
}