Features: Test presence of cxx_auto_type with genex.

The purpose of that test is to cover the case where the genex
reports '1', and the feature is chosen to be present on all/most
supported compilers.  GNU 4.4 does not support cxx_nullptr.

Tests/CompileFeatures/CMakeLists.txt

@@ -194,7 +194,7 @@ if (CMAKE_CXX_COMPILE_FEATURES)
   set_property(TARGET CompileFeaturesGenex PROPERTY CXX_STANDARD 11)
   target_compile_definitions(CompileFeaturesGenex PRIVATE
     HAVE_OVERRIDE_CONTROL=$<COMPILE_FEATURES:cxx_final,cxx_override>
-    HAVE_NULLPTR=$<COMPILE_FEATURES:cxx_nullptr>
+    HAVE_AUTO_TYPE=$<COMPILE_FEATURES:cxx_auto_type>
     HAVE_INHERITING_CONSTRUCTORS=$<COMPILE_FEATURES:cxx_inheriting_constructors>
     HAVE_FINAL=$<COMPILE_FEATURES:cxx_final>
     HAVE_INHERITING_CONSTRUCTORS_AND_FINAL=$<COMPILE_FEATURES:cxx_inheriting_constructors,cxx_final>
@@ -204,7 +204,7 @@ if (CMAKE_CXX_COMPILE_FEATURES)
   target_compile_features(CompileFeaturesGenex2 PRIVATE cxx_static_assert)
   target_compile_definitions(CompileFeaturesGenex2 PRIVATE
     HAVE_OVERRIDE_CONTROL=$<COMPILE_FEATURES:cxx_final,cxx_override>
-    HAVE_NULLPTR=$<COMPILE_FEATURES:cxx_nullptr>
+    HAVE_AUTO_TYPE=$<COMPILE_FEATURES:cxx_auto_type>
     HAVE_INHERITING_CONSTRUCTORS=$<COMPILE_FEATURES:cxx_inheriting_constructors>
     HAVE_FINAL=$<COMPILE_FEATURES:cxx_final>
     HAVE_INHERITING_CONSTRUCTORS_AND_FINAL=$<COMPILE_FEATURES:cxx_inheriting_constructors,cxx_final>
@@ -216,7 +216,7 @@ if (CMAKE_CXX_COMPILE_FEATURES)
   target_link_libraries(CompileFeaturesGenex3 PRIVATE static_assert_iface)
   target_compile_definitions(CompileFeaturesGenex3 PRIVATE
     HAVE_OVERRIDE_CONTROL=$<COMPILE_FEATURES:cxx_final,cxx_override>
-    HAVE_NULLPTR=$<COMPILE_FEATURES:cxx_nullptr>
+    HAVE_AUTO_TYPE=$<COMPILE_FEATURES:cxx_auto_type>
     HAVE_INHERITING_CONSTRUCTORS=$<COMPILE_FEATURES:cxx_inheriting_constructors>
     HAVE_FINAL=$<COMPILE_FEATURES:cxx_final>
     HAVE_INHERITING_CONSTRUCTORS_AND_FINAL=$<COMPILE_FEATURES:cxx_inheriting_constructors,cxx_final>

Tests/CompileFeatures/genex_test.cpp

@@ -17,9 +17,9 @@ struct B final : A
 
 #endif
 
-#if !HAVE_NULLPTR
-#error "Expect nullptr feature"
-#else
+#if !HAVE_AUTO_TYPE
+#  error Expect cxx_auto_type support
+#endif
 
 #if !HAVE_INHERITING_CONSTRUCTORS
 #  if EXPECT_INHERITING_CONSTRUCTORS
@@ -51,13 +51,6 @@ struct B final : A
 #  endif
 #endif
 
-const char* getString()
-{
-  return nullptr;
-}
-
-#endif
-
 int main()
 {