fix scopedeleter diff

Summary: It seems that for some build modes, swig chokes on static_assert, so protect this with #idndef SWIG. Let's see what the tests say....

Reviewed By: algoriddle

Differential Revision: D50971042

fbshipit-source-id: 83e2ccb464c0bd024cbf3a494357147d75a76ca2

Author: mdouze

faiss/impl/platform_macros.h

@@ -151,11 +151,4 @@ inline int __builtin_clzll(uint64_t x) {
 #define FAISS_PRAGMA_IMPRECISE_FUNCTION_END
 #endif
 
-#if defined(_MSC_VER) && defined(_MSVC_LANG)
-static_assert(_MSVC_LANG >= 201703L, "C++17 is expected");
-#else
-// make sure that at least C++17 is used
-static_assert(__cplusplus >= 201703L, "C++17 is expected");
-#endif
-
 // clang-format on