* fix warnings

test=develop

* fix enforce test

test=develop

* Enable cross_entropy operator for a ngraph engine
test=develop

* Update tests
test=develop

* Added PADDLE_ENFORCE for the batch_norm operator
test=develop

* Update the message about which format are supported right now
test=develop

* Correct the comment in control_flow.py.

* Correct the argument list of ops.
test=develop

* Update API.spec.
test=develop

* Skip op_callstack attr for all op apis.
test=develop

* Remove use_mkldnn and is_test from python api.
test=develop

* Remove use_mkldnn and is_test from op_proto_maker and hard-coding them in python when generating doc string.
test=develop

* Add the CRFDecoding and LayerNorm's test case

test=develop

* Fix the size checking issue

test=develop

* Remove the remnant code

test=develop

* Add TestAllImpls and double support

test=develop

* Clean Code

test=develop

* Add benchmark test for LayerNorm & CRFDecoding

test=develop

test=develop

test=develop

test=develop

* inplace group

* test=develop

* fix && test=develop

* fix && test=develop

* test=develop

* Fix debug mode in prior_box_op
* Refine code

test=develop

test=develop

test=develop

* Fix debug mode in fake_quantize_op
* Remove template specialization

* Added ngraph sum op test=develop

* Added sigmoid, relu_grad and tanh_grad test=develop

* remove duplicates test=develop

test=develop

test=develop

* fix aligned-new error in jitkernel

test=develop

* override genbase new to fix mis-align

test=develop

test=develop

test=develop

* Remove some superfluous std::move calls

The std:move triggered a build error (with -Werror):
```
[  9%] Building CXX object paddle/fluid/memory/allocation/CMakeFiles/allocator_facade.dir/allocator_facade.cc.o
/home/tej/code/gbuella_paddle/paddle/fluid/memory/allocation/allocator_facade.cc:86:29: error: moving a temporary object prevents copy elision [-Werror,-Wpessimizing-move]
            [this] { return std::move(CreateAllocatorWithChunk()); }, capacity);
                            ^
/home/tej/code/gbuella_paddle/paddle/fluid/memory/allocation/allocator_facade.cc:86:29: note: remove std::move call here
            [this] { return std::move(CreateAllocatorWithChunk()); }, capacity);
                            ^~~~~~~~~~                          ~
1 error generated.
```

See: https://reviews.llvm.org/D7633

* Remove a superfluous lambda capture from framework/operator.h

```
[ 10%] Building CXX object paddle/fluid/platform/CMakeFiles/device_context.dir/init.cc.o
In file included from /home/tej/code/gbuella_paddle/paddle/fluid/platform/init.cc:19:
/home/tej/code/gbuella_paddle/paddle/fluid/framework/operator.h:229:21: error: lambda capture 'this' is not used [-Werror,-Wunused-lambda-capture]
                   [this](Variable* var) { return var; });
                    ^~~~
1 error generated.
```

Changing it to `return it->second;`, as is in the function below.

* Rethrow an exception (instead of copying it)

```
[ 11%] Building CXX object paddle/fluid/framework/CMakeFiles/operator.dir/operator.cc.o
/home/tej/code/gbuella_paddle/paddle/fluid/framework/operator.cc:191:13: error: local variable 'exception' will be copied despite being thrown by name [-Werror,-Wreturn-std-move]
      throw exception;
            ^~~~~~~~~
/home/tej/code/gbuella_paddle/paddle/fluid/framework/operator.cc:191:13: note: call 'std::move' explicitly to avoid copying
      throw exception;
            ^~~~~~~~~
            std::move(exception)

```

See https://reviews.llvm.org/D43322 for an explanation of this diagnostic message.

* Remove an unused variable

```
/home/tej/code/gbuella_paddle/paddle/fluid/framework/operator.cc:884:16: error: private field 'scope_' is not used [-Werror,-Wunused-private-field]
  const Scope& scope_;
               ^
```

* struct ComputationOpHandle -> class ComputationOpHandle

```
[ 13%] Building CXX object paddle/fluid/framework/details/CMakeFiles/memory_early_delete_pass.dir/memory_early_delete_pass.cc.o
In file included from /home/tej/code/gbuella_paddle/paddle/fluid/framework/details/memory_early_delete_pass.cc:21:
/home/tej/code/gbuella_paddle/paddle/fluid/framework/details/reference_count_pass_helper.h:30:1: error: class 'ComputationOpHandle' was previously declared as a struct; this is valid, but may result in linker errors under the Microsoft C++ ABI [-Werror,-Wmismatched-tags]
class ComputationOpHandle;
^
/home/tej/code/gbuella_paddle/paddle/fluid/framework/details/computation_op_handle.h:29:8: note: previous use is here
struct ComputationOpHandle : public OpHandleBase {
       ^
/home/tej/code/gbuella_paddle/paddle/fluid/framework/details/reference_count_pass_helper.h:30:1: note: did you mean struct here?
class ComputationOpHandle;
^~~~~
struct
1 error generated.
```

* Fix name() methods under fluid/operators

```
In file included from /home/tej/code/gbuella_paddle/paddle/fluid/operators/jit/gen/act.cc:15:
In file included from /home/tej/code/gbuella_paddle/paddle/fluid/operators/jit/gen/act.h:19:
/home/tej/code/gbuella_paddle/paddle/fluid/operators/jit/gen/jitcode.h:71:23: error: 'name' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
  virtual const char* name() const = 0;
                      ^
/home/tej/code/gbuella_paddle/paddle/fluid/operators/jit/gen_base.h:31:23: note: overridden virtual function is here
  virtual const char* name() const = 0;
                      ^
```

test=develop

test=develop

* fix compile issue with_distribute test=develop

* simplified logic test=develop

* use ngraph dependency test=develop

* set cpu only test=develop

* update test and eliminate fp16 test test=develop

test=develop

test=develop

test=develop

test=develop