Build: MSVC 2017 compat (w/o xs code - Perl unit tests)

src/avrdude/windows/unistd.h

@@ -45,7 +45,9 @@ extern "C" {
 #define chdir _chdir
 #define isatty _isatty
 #define lseek _lseek
+#if _MSC_VER < 1900
 #define snprintf _snprintf
+#endif
 #define strncasecmp _strnicmp
 #define strcasecmp _stricmp
 #define stat _stat

src/libslic3r/Int128.hpp

@@ -53,6 +53,11 @@
 	#define HAS_INTRINSIC_128_TYPE
 #endif
 
+#if defined(_MSC_VER) && defined(_WIN64)
+	#include <intrin.h>
+	#pragma intrinsic(_mul128)
+#endif
+
 //------------------------------------------------------------------------------
 // Int128 class (enables safe math on signed 64bit integers)
 // eg Int128 val1((int64_t)9223372036854775807); //ie 2^63 -1