8272806: [macOS] "Apple AWT Internal Exception" when input method is changed

Reviewed-by: serb, dmarkov, azvegint

src/java.desktop/macosx/native/libawt_lwawt/awt/CInputMethod.m

@@ -115,9 +115,7 @@ static void initializeInputMethodController() {
     AWT_ASSERT_APPKIT_THREAD;
 
     if (!view) return;
-    if (!inputMethod) return;
-
-    [view setInputMethod:inputMethod]; // inputMethod is a GlobalRef
+    [view setInputMethod:inputMethod]; // inputMethod is a GlobalRef or null to disable.
 }
 
 + (void) _nativeEndComposition:(AWTView *)view {

src/java.desktop/macosx/native/libawt_lwawt/awt/LWCToolkit.m

@@ -259,6 +259,7 @@ BOOL isSWTInWebStart(JNIEnv* env) {
 
 static void AWT_NSUncaughtExceptionHandler(NSException *exception) {
     NSLog(@"Apple AWT Internal Exception: %@", [exception description]);
+    NSLog(@"trace: %@", [exception callStackSymbols]);
 }
 
 @interface AWTStarter : NSObject