Support for Intel 18

[artv3]

Howdy,

I recently tried building this package with the Intel 18 compiler on Cori, but had no success. I was wondering if we could add support for the Intel 18 compiler? I have errors of the following form:

icpc: command line warning #10121: overriding '-xCORE-AVX2' with '-xMIC-AVX512'
In file included from /global/u2/v/vargas45/Git-Repos/TEST_GEOSX/GEOSX/src/externalComponents/PVTPackage/PVTPackage/source/MultiphaseSystem/MultiphaseSystem.hpp(4),
from /global/u2/v/vargas45/Git-Repos/TEST_GEOSX/GEOSX/src/externalComponents/PVTPackage/PVTPackage/source/MultiphaseSystem/BlackOilMultiphaseSystem.hpp(2),
from /global/u2/v/vargas45/Git-Repos/TEST_GEOSX/GEOSX/src/externalComponents/PVTPackage/PVTPackage/source/MultiphaseSystem/BlackOilMultiphaseSystem.cpp(1):
/usr/include/c++/4.8/bits/hashtable_policy.h(830): error: an incomplete class type is not allowed
bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)>
^
detected during:
processing of template argument list for "std::__detail::_Hashtable_ebo_helper" based on template arguments <1, std::hashPVTPackage::PHASE_TYPE> at line 1073
instantiation of class "std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true> [with _Key=PVTPackage::PHASE_TYPE, _Value=std::pair<const PVTPackage::PHASE_TYPE, PVTPackage::PhaseModel *>, _ExtractKey=std::__detail::_Select1st, _H1=std::hashPVTPackage::PHASE_TYPE, _H2=std::__detail::_Mod_range_hashing]" at line 1403