Java: introduce PsiArrayInitializerExpression.isEmpty() as well (IJ-CR-176760)

GitOrigin-RevId: 2f0757929d780ff01930cc8001001daf59ec4500

java/java-psi-api/src/com/intellij/psi/PsiArrayInitializerExpression.java

@@ -22,4 +22,11 @@ public interface PsiArrayInitializerExpression extends PsiExpression {
   default int getInitializerCount() {
     return getInitializers().length;
   }
+
+  /**
+   * @return {@code true} if this array initializer expression contains no expressions
+   */
+  default boolean isEmpty() {
+    return getInitializerCount() == 0;
+  }
 }