Bug 670091 - Undefined reference to js_myfmod on mingw-w64 (r=m_kato)

js/src/jslibmath.h

@@ -65,7 +65,7 @@ extern double js_copysign(double, double);
 #define js_copysign copysign
 #endif
 
-#if defined(_M_X64) && _MSC_VER <= 1500
+#if defined(_M_X64) && defined(_MSC_VER) && _MSC_VER <= 1500
 // This is a workaround for fmod bug (http://support.microsoft.com/kb/982107)
 extern "C" double js_myfmod(double x, double y);
 #define fmod js_myfmod