Fix _an attribute list cannot appear here_ from clang-cl16

contrib/libs/cxxsupp/libcxx/src/support/runtime/exception_pointer_msvc.ipp

@@ -63,7 +63,7 @@ extern "C" EHExceptionRecord** __current_exception();
 #ifdef __clang__
 struct _ThrowInfo;
 // defined in vcruntime<ver>.dll
-_LIBCPP_NORETURN extern "C" void __stdcall _CxxThrowException(
+extern "C" _LIBCPP_NORETURN void __stdcall _CxxThrowException(
     void* __exc, _ThrowInfo* __throw_info);
 #endif