patch 8.2.3323: Vim9: Cannot use :silent with :endwhile

Problem:    Vim9: Cannot use :silent with :endwhile.
Solution:   Allow for using the :silent modifier. (closes #8737)

runtime/doc/eval.txt

@@ -4539,7 +4539,7 @@ exists({expr})	The result is a Number, which is |TRUE| if {expr} is defined,
 			Varname()->exists()
 <
 
-exists_compiled({expr})						*exists()*
+exists_compiled({expr})					*exists_compiled()*
 		Like `exists()` but evaluated at compile time.  This is useful
 		to skip a block where a function is used that would otherwise
 		give an error: >

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3323,
 /**/
     3322,
 /**/