fixed VS2010 solution

Author: Cyan4973

build/VS2010/libzstd/libzstd.vcxproj

@@ -34,6 +34,7 @@
     <ClCompile Include="..\..\..\lib\compress\zstd_compress_literals.c" />
     <ClCompile Include="..\..\..\lib\compress\zstd_compress_sequences.c" />
     <ClCompile Include="..\..\..\lib\compress\zstd_compress_superblock.c" />
+    <ClCompile Include="..\..\..\lib\compress\zstd_preSplit.c" />
     <ClCompile Include="..\..\..\lib\compress\zstd_fast.c" />
     <ClCompile Include="..\..\..\lib\compress\zstd_double_fast.c" />
     <ClCompile Include="..\..\..\lib\compress\zstd_lazy.c" />