message: [libra-fuzzer] allow fuzzing to work on the beta compiler
  We want to fuzz with the same version of the compiler as production, but cargo-fuzz only
  runs on nightly. This is a test-only environment so this use of RUSTC_BOOTSTRAP seems
  appropriate.
  Closes:
  Approved by: metajack
diff: @@ -97,6 +97,10 @@ pub fn fuzz_target(
  .args(args)
  .current_dir(manifest_dir)
  .env(FuzzTarget::ENV_VAR, target.name())
  + // We want to fuzz with the same version of the compiler as production, but cargo-fuzz only
  + // runs on nightly. This is a test-only environment so this use of RUSTC_BOOTSTRAP seems
  + // appropriate.
  + .env("RUSTC_BOOTSTRAP", "1")
  .status()
  .context("cargo fuzz run errored")?;
  if !status.success() {
  