gpt4all-backend: Add MSVC support to backend (#595)

* Add MSVC compatibility

* Add _MSC_VER macro

---------

Co-authored-by: kuvaus <kuvaus@users.noreply.github.com>

gpt4all-backend/gptj.cpp

@@ -12,7 +12,17 @@
 #include <string>
 #include <vector>
 #include <iostream>
-#include <unistd.h>
+#if defined(_WIN32) && defined(_MSC_VER)
+    #define WIN32_LEAN_AND_MEAN
+    #ifndef NOMINMAX
+        #define NOMINMAX
+    #endif
+    #include <windows.h>
+    #include <io.h>
+    #include <stdio.h>
+#else
+    #include <unistd.h>
+#endif
 #include <sstream>
 #include <unordered_set>
 

gpt4all-backend/llamamodel.cpp

@@ -13,7 +13,17 @@
 #include <string>
 #include <vector>
 #include <iostream>
-#include <unistd.h>
+#if defined(_WIN32) && defined(_MSC_VER)
+    #define WIN32_LEAN_AND_MEAN
+    #ifndef NOMINMAX
+        #define NOMINMAX
+    #endif
+    #include <windows.h>
+    #include <io.h>
+    #include <stdio.h>
+#else
+    #include <unistd.h>
+#endif
 #include <random>
 #include <thread>
 #include <unordered_set>

gpt4all-backend/mpt.cpp

@@ -13,7 +13,17 @@
 #include <string>
 #include <vector>
 #include <iostream>
-#include <unistd.h>
+#if defined(_WIN32) && defined(_MSC_VER)
+    #define WIN32_LEAN_AND_MEAN
+    #ifndef NOMINMAX
+        #define NOMINMAX
+    #endif
+    #include <windows.h>
+    #include <io.h>
+    #include <stdio.h>
+#else
+    #include <unistd.h>
+#endif
 #include <sstream>
 #include <thread>
 #include <unordered_set>