Features: Specify minimum version Intel C++ 12.1

Versions below 12.1 do not provide enough information to properly detect
if compiling with c++98 or c++0x enabled so remove them from the
supported list.

Help/manual/cmake-compile-features.7.rst

@@ -309,3 +309,4 @@ versions specified for each:
 * ``GNU``: GNU compiler versions 4.4 through 5.0.
 * ``MSVC``: Microsoft Visual Studio versions 2010 through 2015.
 * ``SunPro``: Oracle SolarisStudio version 12.4.
+* ``Intel``: Intel compiler versions 12.1 through 16.0 on UNIX platforms.

Modules/Compiler/Intel-CXX-FeatureTests.cmake

@@ -12,7 +12,7 @@ endif()
 #set(_cmake_feature_test_cxx_variable_templates "${Intel15_CXX14}")
 #set(_cmake_feature_test_cxx_relaxed_constexpr "${Intel15_CXX14}")
 
-set(_cmake_oldestSupported "__INTEL_COMPILER >= 1110")
+set(_cmake_oldestSupported "__INTEL_COMPILER >= 1210")
 set(DETECT_CXX11 "((__cplusplus >= 201103L) || defined(__INTEL_CXX11_MODE__) || defined(__GXX_EXPERIMENTAL_CXX0X__))")
 #ICC version 15 update 1 has a bug where __cplusplus is defined as 1 no matter
 #if you are compiling as 98/11/14. So to properly detect C++14 with this version
@@ -71,30 +71,26 @@ set(_cmake_feature_test_cxx_range_for "${Intel13_CXX11}")
 # Cannot find Intel documentation for N2640: cxx_uniform_initialization
 set(_cmake_feature_test_cxx_uniform_initialization "${Intel13_CXX11}")
 
-set(Intel121_CXX11 "__INTEL_COMPILER >= 1210 && ${DETECT_CXX11}")
+set(Intel121_CXX11 "${_cmake_oldestSupported} && ${DETECT_CXX11}")
 set(_cmake_feature_test_cxx_variadic_templates "${Intel121_CXX11}")
 set(_cmake_feature_test_cxx_alias_templates "${Intel121_CXX11}")
 set(_cmake_feature_test_cxx_nullptr "${Intel121_CXX11}")
 set(_cmake_feature_test_cxx_trailing_return_types "${Intel121_CXX11}")
 set(_cmake_feature_test_cxx_attributes "${Intel121_CXX11}")
 set(_cmake_feature_test_cxx_default_function_template_args "${Intel121_CXX11}")
-
-set(Intel12_CXX11 "__INTEL_COMPILER >= 1200 && ${DETECT_CXX11}")
-set(_cmake_feature_test_cxx_extended_friend_declarations "${Intel12_CXX11}")
-set(_cmake_feature_test_cxx_rvalue_references "${Intel12_CXX11}")
-set(_cmake_feature_test_cxx_decltype "${Intel12_CXX11}")
-set(_cmake_feature_test_cxx_defaulted_functions "${Intel12_CXX11}")
-set(_cmake_feature_test_cxx_deleted_functions "${Intel12_CXX11}")
-set(_cmake_feature_test_cxx_local_type_template_args "${Intel12_CXX11}")
-set(_cmake_feature_test_cxx_lambdas "${Intel12_CXX11}")
-
-set(Intel11_CXX11 "${_cmake_oldestSupported} && ${DETECT_CXX11}")
-set(_cmake_feature_test_cxx_binary_literals "${Intel11_CXX11}")
-set(_cmake_feature_test_cxx_static_assert "${Intel11_CXX11}")
-set(_cmake_feature_test_cxx_right_angle_brackets "${Intel11_CXX11}")
-set(_cmake_feature_test_cxx_auto_type "${Intel11_CXX11}")
-set(_cmake_feature_test_cxx_extern_templates "${Intel11_CXX11}")
-set(_cmake_feature_test_cxx_variadic_macros "${Intel11_CXX11}")
-set(_cmake_feature_test_cxx_long_long_type "${Intel11_CXX11}")
-set(_cmake_feature_test_cxx_func_identifier "${Intel11_CXX11}")
-set(_cmake_feature_test_cxx_template_template_parameters "${Intel11_CXX11}")
+set(_cmake_feature_test_cxx_extended_friend_declarations "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_rvalue_references "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_decltype "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_defaulted_functions "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_deleted_functions "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_local_type_template_args "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_lambdas "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_binary_literals "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_static_assert "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_right_angle_brackets "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_auto_type "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_extern_templates "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_variadic_macros "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_long_long_type "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_func_identifier "${Intel121_CXX11}")
+set(_cmake_feature_test_cxx_template_template_parameters "${Intel121_CXX11}")