tests/run-make/target-specs/definitely-not-builtin-target.json

{
  "arch": "x86_64",
  "is-builtin": true,
  "data-layout": "e-m:e-i64:64-f80:128-n8:16:32:64-S128",
  "llvm-target": "x86_64-unknown-unknown-gnu",
  "target-pointer-width": "64"
}