message: Implements the experimental "C API" Compile/Execute Program.
diff: @@ -54,11 +54,13 @@ typedef struct TpuLoadedProgramHandle {
  } TpuLoadedProgramHandle;
  typedef struct HloProto {
  - // TODO(b/146662059): this is a temp plug for xla::HloProto
  + void* bytes;
  + int32_t size;
  } HloProto;
  typedef struct DeviceAssignmentProto {
  - // TODO(b/146662059): this is a temp plug for xla::DeviceAssignmentProto
  + void* bytes;
  + int32_t size;
  } DeviceAssignmentProto;
  typedef struct TpuStatus {
  @@ -91,7 +93,7 @@ typedef struct TpuEvent*(PrototypeTpuDriver_ExecuteProgram)(
  struct TpuDriver* driver, struct TpuLoadedProgramHandle* handle,
  int32_t inputc, struct TpuBufferHandle** input_buffer_handle,
  int32_t outputc, struct TpuBufferHandle** output_buffer_handle,
  - const DeviceAssignmentProto& device_assignment, int32_t eventc,
  + const struct DeviceAssignmentProto& device_assignment, int32_t eventc,
  struct TpuEvent** eventv);
  typedef struct TpuBufferHandle*(PrototypeTpuDriver_AllocateTuple)(
  