patch 8.2.4552: in a :def function "put = expr" does not work

Problem:    In a :def function "put = expr" does not work.
Solution:   Skip over white space. (closes #9936)

src/testdir/test_vim9_cmd.vim

@@ -1217,7 +1217,7 @@ def Test_put_command()
   :2put =['a', 'b', 'c']
   assert_equal(['ppp', 'a', 'b', 'c', 'above'], getline(2, 6))
 
-  :0put ='first'
+  :0put =  'first'
   assert_equal('first', getline(1))
   :1put! ='first again'
   assert_equal('first again', getline(1))

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4552,
 /**/
     4551,
 /**/

src/vim9cmds.c

@@ -1767,7 +1767,7 @@ compile_put(char_u *arg, exarg_T *eap, cctx_T *cctx)
 
     if (eap->regname == '=')
     {
-	char_u *p = line + 1;
+	char_u *p = skipwhite(line + 1);
 
 	if (compile_expr0(&p, cctx) == FAIL)
 	    return NULL;