message: Fix ASCII art header
diff: -//===-- ThreadLauncher.cpp ---------------------------------------*- C++
  -//-*-===//
  +//===-- ThreadLauncher.cpp --------------------------------------*- C++ -*-===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  