Fix the C2678 MSVC compilation error
Fix the C2678 MSVC compilation error

MSVC 14.15 returns the C2678 error during a compilation of the
'tensorflow/core/kernels/data/scan_dataset_op.cc' unit:

C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.15.26726\include\xmemory(217):
error C2678: binary '*': no operator found which takes a left-hand
operand of type 'const _Iter' (or there is no acceptable conversion)
with
[
    _Iter=tensorflow::OpInputList::Iterator
]

.\tensorflow/core/framework/op_kernel.h(405):
note: could be 'const tensorflow::Tensor &tensorflow::OpArgIterator<tensorflow::OpInputList,
    const tensorflow::Tensor>::operator *(void)'

Two const operator functions: 'operator*() const' and 'operator->()
const', returning a const pointer or const reference respectively,
have been added to the 'OpArgIterator' template class.

Signed-off-by: Pavel Samolysov <6f1fcf954d441b01751b39f5c198405aaa04dae3@gmail.com>

gautam1858/tensorflow,gautam1858/tensorflow,aam-at/tensorflow,arborh/tensorflow,adit-chandra/tensorflow,jbedorf/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,ageron/tensorflow,freedomtan/tensorflow,aam-at/tensorflow,aam-at/tensorflow,jbedorf/tensorflow,apark263/tensorflow,jendap/tensorflow,jhseu/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,sarvex/tensorflow,tensorflow/tensorflow,karllessard/tensorflow,theflofly/tensorflow,gunan/tensorflow,alsrgv/tensorflow,aldian/tensorflow,arborh/tensorflow,annarev/tensorflow,frreiss/tensorflow-fred,petewarden/tensorflow,jbedorf/tensorflow,arborh/tensorflow,tensorflow/tensorflow,jbedorf/tensorflow,alsrgv/tensorflow,ghchinoy/tensorflow,xzturn/tensorflow,adit-chandra/tensorflow,tensorflow/tensorflow,annarev/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,arborh/tensorflow,petewarden/tensorflow,gunan/tensorflow,Intel-tensorflow/tensorflow,chemelnucfin/tensorflow,Intel-Corporation/tensorflow,jhseu/tensorflow,xzturn/tensorflow,theflofly/tensorflow,adit-chandra/tensorflow,karllessard/tensorflow,petewarden/tensorflow,petewarden/tensorflow,alsrgv/tensorflow,yongtang/tensorflow,karllessard/tensorflow,apark263/tensorflow,yongtang/tensorflow,gunan/tensorflow,karllessard/tensorflow,ppwwyyxx/tensorflow,ghchinoy/tensorflow,petewarden/tensorflow,DavidNorman/tensorflow,aldian/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,chemelnucfin/tensorflow,renyi533/tensorflow,yongtang/tensorflow,davidzchen/tensorflow,paolodedios/tensorflow,chemelnucfin/tensorflow,adit-chandra/tensorflow,yongtang/tensorflow,Intel-tensorflow/tensorflow,hfp/tensorflow-xsmm,ageron/tensorflow,ppwwyyxx/tensorflow,petewarden/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,freedomtan/tensorflow,theflofly/tensorflow,paolodedios/tensorflow,gautam1858/tensorflow,jbedorf/tensorflow,ageron/tensorflow,frreiss/tensorflow-fred,cxxgtxy/tensorflow,annarev/tensorflow,gunan/tensorflow,apark263/tensorflow,Intel-Corporation/tensorflow,davidzchen/tensorflow,adit-chandra/tensorflow,ageron/tensorflow,aam-at/tensorflow,apark263/tensorflow,ageron/tensorflow,gautam1858/tensorflow,ppwwyyxx/tensorflow,aldian/tensorflow,adit-chandra/tensorflow,aam-at/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-experimental_link_static_libraries_once,jendap/tensorflow,gunan/tensorflow,Intel-Corporation/tensorflow,gautam1858/tensorflow,ppwwyyxx/tensorflow,apark263/tensorflow,annarev/tensorflow,davidzchen/tensorflow,aam-at/tensorflow,davidzchen/tensorflow,renyi533/tensorflow,davidzchen/tensorflow,paolodedios/tensorflow,alsrgv/tensorflow,kevin-coder/tensorflow-fork,yongtang/tensorflow,ppwwyyxx/tensorflow,jbedorf/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,DavidNorman/tensorflow,DavidNorman/tensorflow,paolodedios/tensorflow,hfp/tensorflow-xsmm,freedomtan/tensorflow,aldian/tensorflow,paolodedios/tensorflow,kevin-coder/tensorflow-fork,ghchinoy/tensorflow,aldian/tensorflow,arborh/tensorflow,aldian/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_saved_model,xzturn/tensorflow,apark263/tensorflow,freedomtan/tensorflow,adit-chandra/tensorflow,hfp/tensorflow-xsmm,annarev/tensorflow,Intel-tensorflow/tensorflow,renyi533/tensorflow,tensorflow/tensorflow,alsrgv/tensorflow,alsrgv/tensorflow,Intel-tensorflow/tensorflow,petewarden/tensorflow,adit-chandra/tensorflow,ageron/tensorflow,davidzchen/tensorflow,yongtang/tensorflow,xzturn/tensorflow,adit-chandra/tensorflow,hfp/tensorflow-xsmm,annarev/tensorflow,theflofly/tensorflow,cxxgtxy/tensorflow,ppwwyyxx/tensorflow,petewarden/tensorflow,paolodedios/tensorflow,theflofly/tensorflow,theflofly/tensorflow,alsrgv/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,aam-at/tensorflow,frreiss/tensorflow-fred,xzturn/tensorflow,DavidNorman/tensorflow,tensorflow/tensorflow,gunan/tensorflow,kevin-coder/tensorflow-fork,ageron/tensorflow,aldian/tensorflow,apark263/tensorflow,hfp/tensorflow-xsmm,aldian/tensorflow,jendap/tensorflow,DavidNorman/tensorflow,Intel-tensorflow/tensorflow,jhseu/tensorflow,renyi533/tensorflow,Intel-tensorflow/tensorflow,paolodedios/tensorflow,jbedorf/tensorflow,Intel-Corporation/tensorflow,jhseu/tensorflow,kevin-coder/tensorflow-fork,chemelnucfin/tensorflow,frreiss/tensorflow-fred,jbedorf/tensorflow,jhseu/tensorflow,frreiss/tensorflow-fred,jendap/tensorflow,ghchinoy/tensorflow,Intel-tensorflow/tensorflow,ppwwyyxx/tensorflow,tensorflow/tensorflow-pywrap_saved_model,theflofly/tensorflow,davidzchen/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_saved_model,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,annarev/tensorflow,freedomtan/tensorflow,ppwwyyxx/tensorflow,frreiss/tensorflow-fred,jbedorf/tensorflow,freedomtan/tensorflow,tensorflow/tensorflow-pywrap_saved_model,aam-at/tensorflow,DavidNorman/tensorflow,ppwwyyxx/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,davidzchen/tensorflow,ppwwyyxx/tensorflow,paolodedios/tensorflow,kevin-coder/tensorflow-fork,gunan/tensorflow,ghchinoy/tensorflow,freedomtan/tensorflow,jbedorf/tensorflow,ppwwyyxx/tensorflow,ageron/tensorflow,cxxgtxy/tensorflow,jhseu/tensorflow,ghchinoy/tensorflow,freedomtan/tensorflow,annarev/tensorflow,paolodedios/tensorflow,chemelnucfin/tensorflow,theflofly/tensorflow,DavidNorman/tensorflow,yongtang/tensorflow,Intel-tensorflow/tensorflow,adit-chandra/tensorflow,aam-at/tensorflow,tensorflow/tensorflow,gunan/tensorflow,hfp/tensorflow-xsmm,sarvex/tensorflow,jendap/tensorflow,gunan/tensorflow,Intel-Corporation/tensorflow,Intel-Corporation/tensorflow,adit-chandra/tensorflow,arborh/tensorflow,xzturn/tensorflow,gautam1858/tensorflow,frreiss/tensorflow-fred,aam-at/tensorflow,sarvex/tensorflow,ghchinoy/tensorflow,karllessard/tensorflow,ghchinoy/tensorflow,ageron/tensorflow,gautam1858/tensorflow,ageron/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-pywrap_saved_model,paolodedios/tensorflow,yongtang/tensorflow,Intel-tensorflow/tensorflow,jhseu/tensorflow,arborh/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,Intel-Corporation/tensorflow,tensorflow/tensorflow,petewarden/tensorflow,jendap/tensorflow,DavidNorman/tensorflow,cxxgtxy/tensorflow,cxxgtxy/tensorflow,Intel-Corporation/tensorflow,jhseu/tensorflow,tensorflow/tensorflow-pywrap_saved_model,hfp/tensorflow-xsmm,jbedorf/tensorflow,cxxgtxy/tensorflow,DavidNorman/tensorflow,renyi533/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,ppwwyyxx/tensorflow,chemelnucfin/tensorflow,xzturn/tensorflow,ghchinoy/tensorflow,arborh/tensorflow,freedomtan/tensorflow,ghchinoy/tensorflow,annarev/tensorflow,renyi533/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,chemelnucfin/tensorflow,sarvex/tensorflow,davidzchen/tensorflow,sarvex/tensorflow,gunan/tensorflow,theflofly/tensorflow,sarvex/tensorflow,cxxgtxy/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,arborh/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,karllessard/tensorflow,frreiss/tensorflow-fred,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,chemelnucfin/tensorflow,annarev/tensorflow,sarvex/tensorflow,jendap/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,DavidNorman/tensorflow,ageron/tensorflow,Intel-tensorflow/tensorflow,theflofly/tensorflow,freedomtan/tensorflow,frreiss/tensorflow-fred,DavidNorman/tensorflow,adit-chandra/tensorflow,frreiss/tensorflow-fred,petewarden/tensorflow,arborh/tensorflow,yongtang/tensorflow,renyi533/tensorflow,alsrgv/tensorflow,kevin-coder/tensorflow-fork,kevin-coder/tensorflow-fork,theflofly/tensorflow,aam-at/tensorflow,arborh/tensorflow,tensorflow/tensorflow,gunan/tensorflow,kevin-coder/tensorflow-fork,karllessard/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,apark263/tensorflow,petewarden/tensorflow,petewarden/tensorflow,alsrgv/tensorflow,alsrgv/tensorflow,xzturn/tensorflow,karllessard/tensorflow,gautam1858/tensorflow,gautam1858/tensorflow,xzturn/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,jendap/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,freedomtan/tensorflow,apark263/tensorflow,karllessard/tensorflow,jendap/tensorflow,karllessard/tensorflow,alsrgv/tensorflow,annarev/tensorflow,alsrgv/tensorflow,jhseu/tensorflow,renyi533/tensorflow,tensorflow/tensorflow-pywrap_saved_model,hfp/tensorflow-xsmm,chemelnucfin/tensorflow,kevin-coder/tensorflow-fork,tensorflow/tensorflow-pywrap_tf_optimizer,jbedorf/tensorflow,xzturn/tensorflow,renyi533/tensorflow,xzturn/tensorflow,apark263/tensorflow,hfp/tensorflow-xsmm,ghchinoy/tensorflow,cxxgtxy/tensorflow,Intel-tensorflow/tensorflow,apark263/tensorflow,arborh/tensorflow,gautam1858/tensorflow,jhseu/tensorflow,ageron/tensorflow,hfp/tensorflow-xsmm,tensorflow/tensorflow,jhseu/tensorflow,davidzchen/tensorflow,jendap/tensorflow,xzturn/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,renyi533/tensorflow,davidzchen/tensorflow,tensorflow/tensorflow-pywrap_saved_model,freedomtan/tensorflow,jendap/tensorflow,kevin-coder/tensorflow-fork,kevin-coder/tensorflow-fork,renyi533/tensorflow,yongtang/tensorflow,chemelnucfin/tensorflow,tensorflow/tensorflow,gunan/tensorflow,hfp/tensorflow-xsmm,tensorflow/tensorflow-pywrap_tf_optimizer,DavidNorman/tensorflow,karllessard/tensorflow,chemelnucfin/tensorflow,aam-at/tensorflow,davidzchen/tensorflow,sarvex/tensorflow,jhseu/tensorflow,tensorflow/tensorflow,renyi533/tensorflow,chemelnucfin/tensorflow,ghchinoy/tensorflow,theflofly/tensorflow