throw no more handles if a timer could not be created

[jonahgraham]

At the moment the code silently fails on calling timerExec if there are no handles left or it fails for other reasons.

Relates to #2806 where we can see that we are running out of handles, but the timerExec does not report a failure.

[jonahgraham]

This is a draft for now because it needs consideration for other platforms and whether after 25 years there is a reason that this case was allowed to fail silently on Windows.

On macOS there is a pointless null check in the same place because an NPE would have already been raised. On GTK I need to investigate more because the functions are not documented as being able to fail.

macOS:

eclipse.platform.swt/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Display.java

Lines 5381 to 5390 in bb954ac

	NSTimer timer = NSTimer.scheduledTimerWithTimeInterval(milliseconds / 1000.0, timerDelegate, OS.sel_timerProc_, userInfo, false);
	NSRunLoop runLoop = NSRunLoop.currentRunLoop();
	runLoop.addTimer(timer, OS.NSModalPanelRunLoopMode);
	runLoop.addTimer(timer, OS.NSEventTrackingRunLoopMode);
	timer.retain();
	if (timer != null) {
	nsTimers [index] = timer;
	timerList [index] = runnable;
	}
	}

GTK:

eclipse.platform.swt/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java

Lines 5750 to 5759 in 286e614

	if (GTK.GTK4) {
	timerId = OS.g_timeout_add (milliseconds, timerProc, index);
	} else {
	timerId = GDK.gdk_threads_add_timeout (milliseconds, timerProc, index);
	}
	if (timerId != 0) {
	timerIds [index] = timerId;
	timerList [index] = runnable;
	}
	}

[github-actions]

Test Results

  115 files   -  3    115 suites   - 3   10m 36s ⏱️ - 7m 10s
4 616 tests  - 37  4 598 ✅  - 38  18 💤 +1  0 ❌ ±0 
  320 runs   - 18    317 ✅  - 17   3 💤  - 1  0 ❌ ±0 

Results for commit 37b2026. ± Comparison against base commit 28bb9b4.

This pull request removes 37 tests.

AllGTKTests Test_GtkConverter ‑ test_HeuristicASCII_dollarSign
AllGTKTests Test_GtkConverter ‑ test_HeuristicASCII_emptyString
AllGTKTests Test_GtkConverter ‑ test_HeuristicASCII_letterA
AllGTKTests Test_GtkConverter ‑ test_HeuristicASCII_letters
AllGTKTests Test_GtkConverter ‑ test_HeuristicUTF16LE_null
AllGTKTests Test_GtkConverter ‑ test_HeuristicUTF16_AsciiLetters
AllGTKTests Test_GtkConverter ‑ test_HeuristicUTF16_Asciiletter
AllGTKTests Test_GtkConverter ‑ test_HeuristicUTF16_LotsOfLetters
AllGTKTests Test_GtkConverter ‑ test_HeuristicUTF16_letter
AllGTKTests Test_GtkConverter ‑ test_HeuristicUTF16_letters
…

This pull request skips 3 tests.

org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_setUrl_remote_with_post
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser_IE ‑ test_setUrl_remote_with_post
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_widgets_Shell ‑ test_activateEventSend