Don't check if __cplusplus is defined

Author: horenmar

src/catch2/internal/catch_compiler_capabilities.hpp

@@ -27,16 +27,12 @@
 #include <catch2/internal/catch_platform.hpp>
 #include <catch2/catch_user_config.hpp>
 
-#ifdef __cplusplus
-
-#  if (__cplusplus >= 201703L) || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
-#    define CATCH_CPP17_OR_GREATER
-#  endif
-
-#  if (__cplusplus >= 202002L) || (defined(_MSVC_LANG) && _MSVC_LANG >= 202002L)
-#    define CATCH_CPP20_OR_GREATER
-#  endif
+#if (__cplusplus >= 201703L) || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
+#  define CATCH_CPP17_OR_GREATER
+#endif
 
+#if (__cplusplus >= 202002L) || (defined(_MSVC_LANG) && _MSVC_LANG >= 202002L)
+#  define CATCH_CPP20_OR_GREATER
 #endif
 
 // Only GCC compiler should be used in this block, so other compilers trying to