Removed the dummy NSEvent code from bleh_darwin.m and rewrote it in Objective-C in delegateuitask_darwin.m. And now to nuke bleh_darwin.m and change all the int64_ts to intptr_ts and merge the .h files...

bleh_darwin.m

@@ -64,20 +64,3 @@ void initBleh()
 	s_initTrackingArea = sel_getUid("initWithRect:options:owner:userInfo:");
 }
 
-/*
-See uitask_darwin.go: we need to synthesize a NSEvent so -[NSApplication stop:] will work. We cannot simply init the default NSEvent though (it throws an exception) so we must do it "the right way". This involves a very convoluted initializer; we'll just do it here to keep things clean on the Go side (this will only be run once anyway, on program exit).
-*/
-
-id makeDummyEvent()
-{
-	return objc_msgSend(c_NSEvent, s_newEvent,
-		(NSUInteger) NSApplicationDefined,			/* otherEventWithType: */
-		NSMakePoint(0, 0),						/* location: */
-		(NSUInteger) 0,							/* modifierFlags: */
-		(double) 0,							/* timestamp: */
-		(NSInteger) 0,							/* windowNumber: */
-		nil,									/* context: */
-		(short) 0,								/* subtype: */
-		(NSInteger) 0,							/* data1: */
-		(NSInteger) 0);							/* data2: */
-}

delegateuitask_darwin.m

@@ -9,6 +9,7 @@
 #include <AppKit/NSApplication.h>
 #include <AppKit/NSWindow.h>
 #include <Foundation/NSAutoreleasePool.h>
+#include <AppKit/NSEvent.h>
 
 @interface appDelegate : NSObject
 @end
@@ -80,13 +81,23 @@ void douitask(id appDelegate, void *p)
 
 void breakMainLoop(void)
 {
+	NSEvent *e;
+
 	// -[NSApplication stop:] stops the event loop; it won't do a clean termination, but we're not too concerned with that (at least not on the other platforms either so)
 	// we can't call -[NSApplication terminate:] because that will just quit the program, ensuring we never leave ui.Go()
 	[NSApp stop:NSApp];
 	// simply calling -[NSApplication stop:] is not good enough, as the stop flag is only checked when an event comes in
 	// we have to create a "proper" event; a blank event will just throw an exception
-	[NSApp postEvent:makeDummyEvent()		// TODO inline this
-		atStart:NO];			// not at start, just in case there are other events pending (TODO is this correct?)
+	e = [NSEvent otherEventWithType:NSApplicationDefined
+		location:NSZeroPoint
+		modifierFlags:0
+		timestamp:0
+		windowNumber:0
+		context:nil
+		subtype:0
+		data1:0
+		data2:0];
+	[NSApp postEvent:e atStart:NO];			// not at start, just in case there are other events pending (TODO is this correct?)
 }
 
 void cocoaMainLoop(void)

objc_darwin.h

@@ -51,6 +51,5 @@ struct xpoint {
 
 /* for uitask_darwin.go */
 extern void initBleh();
-extern id makeDummyEvent();
 
 #endif