Fix building the Mac version with GUI.
diff --git a/src/proto/gui_mac.pro b/src/proto/gui_mac.pro
index 29ab9d3..ba6e2ad 100644
--- a/src/proto/gui_mac.pro
+++ b/src/proto/gui_mac.pro
@@ -139,6 +139,7 @@
void gui_mac_doMouseDownEvent __ARGS((EventRecord *theEvent));
void gui_mac_doMouseMovedEvent __ARGS((EventRecord *event));
void gui_mac_doMouseUpEvent __ARGS((EventRecord *theEvent));
+void gui_mch_mousehide __ARGS((int hide));
int C2PascalString (char_u *CString, Str255 *PascalString);
int GetFSSpecFromPath ( char_u *file, FSSpec *fileFSSpec);