patch 9.0.1490: the ModeChanged event may be triggered too often

Problem:    The ModeChanged event may be triggered too often.
Solution:   Only trigger ModeChanged when no operator is pending.
            (closes #12298)
diff --git a/src/normal.c b/src/normal.c
index 1b5326b..2f3d12a 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -975,12 +975,15 @@
 	reset_reg_var();
 #endif
 
-    // Reset finish_op, in case it was set
 #ifdef CURSOR_SHAPE
     int prev_finish_op = finish_op;
 #endif
-    finish_op = FALSE;
-    may_trigger_modechanged();
+    if (oap->op_type == OP_NOP)
+    {
+	// Reset finish_op, in case it was set
+	finish_op = FALSE;
+	may_trigger_modechanged();
+    }
 #ifdef CURSOR_SHAPE
     // Redraw the cursor with another shape, if we were in Operator-pending
     // mode or did a replace command.
@@ -995,7 +998,7 @@
 #endif
 
     if (oap->op_type == OP_NOP && oap->regname == 0
-	    && ca.cmdchar != K_CURSORHOLD)
+						 && ca.cmdchar != K_CURSORHOLD)
 	clear_showcmd();
 
     checkpcmark();		// check if we moved since setting pcmark
@@ -1496,9 +1499,9 @@
 }
 
 /*
- * check for operator active and clear it
+ * Check for operator active and clear it.
  *
- * return TRUE if operator was active
+ * Beep and return TRUE if an operator was active.
  */
     static int
 checkclearop(oparg_T *oap)
@@ -1512,7 +1515,7 @@
 /*
  * Check for operator or Visual active.  Clear active operator.
  *
- * Return TRUE if operator or Visual was active.
+ * Beep and return TRUE if an operator or Visual was active.
  */
     static int
 checkclearopq(oparg_T *oap)