Workaround for MSVC 17.8 bug (#333)

* Workaround for MSVC 17.8 bug

fixes #330

* Bugfix to the bugfix

Author: adamjw24

source/Lib/CommonLib/x86/InitX86.cpp

@@ -147,11 +147,14 @@ void LoopFilter::initLoopFilterX86()
 void RdCost::initRdCostX86()
 {
   auto vext = read_x86_extension_flags();
-  switch (vext){
+  switch (vext){ 
     case AVX512:
     case AVX2:
+#if defined( _MSC_VER ) && _MSC_VER >= 1938
+#else
       _initRdCostX86<AVX2>();
       break;
+#endif
     case AVX:
       _initRdCostX86<AVX>();
       break;