message: Add DCHECK to ScopedDeviceMemory constructor.
  This lets some error cases fail faster.
diff: @@ -59,7 +59,9 @@ class ScopedDeviceMemory {
  // out of scope.
  ScopedDeviceMemory(DeviceMemoryBase mem, int device_ordinal,
  DeviceMemoryAllocator *allocator)
  - : wrapped_(mem), device_ordinal_(device_ordinal), allocator_(allocator) {}
  + : wrapped_(mem), device_ordinal_(device_ordinal), allocator_(allocator) {
  + DCHECK_GE(device_ordinal_, 0);
  + }
  // A helper constructor to generate a scoped device memory given an already
  // allocated memory and a stream executor.
  @@ -79,8 +81,9 @@ class ScopedDeviceMemory {
  //
  // Postcondition: other == nullptr.
  ScopedDeviceMemory(ScopedDeviceMemory &&other)
  - : ScopedDeviceMemory(other.Release(), other.device_ordinal_,
  - other.allocator_) {}
  + : wrapped_(other.Release()),
  + device_ordinal_(other.device_ordinal_),
  + allocator_(other.allocator_) {}
  // Releases the memory that was provided in the constructor, through the
  // "parent" StreamExecutor.
  