Fix find/replace overlay asyncExecIfOpen running on disposed container

The inner guard inside the asyncExec callback of the find/replace
overlay's asyncExecIfOpen method used || instead of && and was missing
the negation on isDisposed(). Because containerControl is an instance
field set once at construction and never cleared, the sub-expression
`containerControl != null` is unconditionally true. Combined with ||
this caused the entire condition to always short-circuit to true, making
the isDisposed() branch dead code and the guard ineffective.

As a result, the async callback could invoke operation.run() even after
containerControl had been disposed in the window between the outer check
and the callback executing. The sole caller passes
FindReplaceOverlay::updatePlacementAndVisibility, which calls
requestLayout(), setSize(), setLocation() and layout() directly on
containerControl. Executing those calls on a disposed widget throws an
SWTException ("Widget is disposed").

Fix by changing the condition to `containerControl != null &&
!containerControl.isDisposed()`, which correctly re-checks liveness
before running the operation.

Author: HeikoKlare

bundles/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/findandreplace/overlay/FindReplaceOverlay.java

@@ -352,7 +352,7 @@ private void performSelectAll() {
 	private void asyncExecIfOpen(Runnable operation) {
 		if (!containerControl.isDisposed()) {
 			containerControl.getDisplay().asyncExec(() -> {
-				if (containerControl != null || containerControl.isDisposed()) {
+				if (containerControl != null && !containerControl.isDisposed()) {
 					operation.run();
 				}
 			});