SunPro: Record support for C++14 features by SunPro 5.{14,15}

SunPro 5.15 supports `-std=c++14` and several C++14 features.

SunPro 5.14 accepts `-std=c++14` but does not update its definition of
`__cplusplus` or any other macro to distinguish it from `-std=c++11`,
so we need to blacklist a couple features that do work but that we
cannot report for that version.  We can still support `cxx_std_14`.

Co-Author: Robert Maynard <robert.maynard@kitware.com>

Modules/Compiler/SunPro-CXX-FeatureTests.cmake

@@ -6,6 +6,14 @@
 
 set(_cmake_oldestSupported "__SUNPRO_CC >= 0x5130")
 
+set(SolarisStudio126_CXX14 "(__SUNPRO_CC >= 0x5150) && __cplusplus >= 201402L")
+set(_cmake_feature_test_cxx_aggregate_default_initializers "${SolarisStudio126_CXX14}")
+set(_cmake_feature_test_cxx_digit_separators "${SolarisStudio126_CXX14}")
+set(_cmake_feature_test_cxx_generic_lambdas "${SolarisStudio126_CXX14}")
+set(_cmake_feature_test_cxx_lambda_init_captures "${SolarisStudio126_CXX14}")
+set(_cmake_feature_test_cxx_return_type_deduction "${SolarisStudio126_CXX14}")
+set(_cmake_feature_test_cxx_variable_templates "${SolarisStudio126_CXX14}")
+
 set(SolarisStudio126_CXX11 "(__SUNPRO_CC >= 0x5150) && __cplusplus >= 201103L")
 set(_cmake_feature_test_cxx_decltype_auto "${SolarisStudio126_CXX11}")
 

Modules/Compiler/SunPro-CXX.cmake

@@ -52,6 +52,11 @@ if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.13)
   set(CMAKE_CXX11_STANDARD_COMPILE_OPTION "-std=c++11")
   set(CMAKE_CXX11_EXTENSION_COMPILE_OPTION "-std=c++11")
   set(CMAKE_CXX_LINK_WITH_STANDARD_COMPILE_OPTION 1)
+
+  if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.14)
+    set(CMAKE_CXX14_STANDARD_COMPILE_OPTION "-std=c++14")
+    set(CMAKE_CXX14_EXTENSION_COMPILE_OPTION "-std=c++14")
+  endif()
 else()
   set(CMAKE_CXX98_STANDARD_COMPILE_OPTION "-library=stlport4")
   set(CMAKE_CXX98_EXTENSION_COMPILE_OPTION "-library=stlport4")

Tests/CompileFeatures/CMakeLists.txt

@@ -52,6 +52,16 @@ if (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang"
 endif()
 
 if (CMAKE_CXX_COMPILER_ID STREQUAL SunPro)
+  if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.15)
+    # SunPro 5.14 accepts -std=c++14 and compiles two features but does
+    # not define __cplusplus to a value different than with -std=c++11.
+    list(REMOVE_ITEM CXX_non_features
+      cxx_aggregate_default_initializers
+      cxx_digit_separators
+    )
+  endif()
+
+  # FIXME: Do any of these work correctly on SunPro 5.13 or above?
   list(REMOVE_ITEM CXX_non_features
     cxx_attribute_deprecated
     cxx_contextual_conversions