patch 8.2.1637: Vim9: :put ={expr} does not work inside :def function

Problem:    Vim9: :put ={expr} does not work inside :def function.
Solution:   Add ISN_PUT. (closes #6397)
diff --git a/src/edit.c b/src/edit.c
index 2cc0ce0..642ff95 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -3399,7 +3399,7 @@
 	    AppendCharToRedobuff(literally);
 	    AppendCharToRedobuff(regname);
 
-	    do_put(regname, BACKWARD, 1L,
+	    do_put(regname, NULL, BACKWARD, 1L,
 		 (literally == Ctrl_P ? PUT_FIXINDENT : 0) | PUT_CURSEND);
 	}
 	else if (insert_reg(regname, literally) == FAIL)
@@ -4776,7 +4776,7 @@
     static void
 ins_drop(void)
 {
-    do_put('~', BACKWARD, 1L, PUT_CURSEND);
+    do_put('~', NULL, BACKWARD, 1L, PUT_CURSEND);
 }
 #endif