message: [ThreadLauncher] Use mapWindowsError and LLDB_INVALID_HOST_THREAD
  Address post-commit feedback from Pavel and Jim.
diff: @@ -31,10 +31,8 @@ llvm::Expected<HostThread> ThreadLauncher::LaunchThread(
  thread = (lldb::thread_t)::_beginthreadex(
  0, (unsigned)min_stack_byte_size,
  HostNativeThread::ThreadCreateTrampoline, info_ptr, 0, NULL);
  - if (thread == (lldb::thread_t)(-1L)) {
  - DWORD err = GetLastError();
  - return llvm::errorCodeToError(std::error_code(err, std::system_category()));
  - }
  + if (thread == LLDB_INVALID_HOST_THREAD)
  + return llvm::errorCodeToError(llvm::mapWindowsError(GetLastError()));
  #else
  // ASAN instrumentation adds a lot of bookkeeping overhead on stack frames.
  