Fix MSVC compilation errors

core/os/file_access.h

@@ -140,7 +140,7 @@ public:
 
 	virtual Error reopen(const String &p_path, int p_mode_flags); ///< does not change the AccessType
 
-	virtual Error _chmod(const String &p_path, int p_mod) {}
+	virtual Error _chmod(const String &p_path, int p_mod) { return FAILED; }
 
 	static FileAccess *create(AccessType p_access); /// Create a file access (for the current platform) this is the only portable way of accessing files.
 	static FileAccess *create_for_path(const String &p_path);

modules/gdnative/gdnative.cpp

@@ -40,8 +40,8 @@
 const String init_symbol = "godot_gdnative_init";
 const String terminate_symbol = "godot_gdnative_terminate";
 
-#define GDAPI_FUNC(name, ret_type, ...) .name = name,
-#define GDAPI_FUNC_VOID(name, ...) .name = name,
+#define GDAPI_FUNC(name, ret_type, ...) name,
+#define GDAPI_FUNC_VOID(name, ...) name,
 
 const godot_gdnative_api_struct api_struct = {
 	GODOT_GDNATIVE_API_FUNCTIONS