patch 8.2.1159: Vim9: no error for missing space after a comma

Problem:    Vim9: no error for missing space after a comma.
Solution:   Check for white space.

src/testdir/test_vim9_expr.vim

@@ -1014,6 +1014,7 @@ def Test_expr7_list()
 
   call CheckDefExecFailure(["let x = g:anint[3]"], 'E714:')
   call CheckDefFailure(["let x = g:list_mixed[xxx]"], 'E1001:')
+  call CheckDefFailure(["let x = [1,2,3]"], 'E1069:')
   call CheckDefExecFailure(["let x = g:list_mixed['xx']"], 'E39:')
   call CheckDefFailure(["let x = g:list_mixed[0"], 'E111:')
   call CheckDefExecFailure(["let x = g:list_empty[3]"], 'E684:')

src/testdir/test_vim9_script.vim

@@ -571,7 +571,7 @@ enddef
 
 def Test_try_catch_fails()
   call CheckDefFailure(['catch'], 'E603:')
-  call CheckDefFailure(['try', 'echo 0', 'catch','catch'], 'E1033:')
+  call CheckDefFailure(['try', 'echo 0', 'catch', 'catch'], 'E1033:')
   call CheckDefFailure(['try', 'echo 0', 'catch /pat'], 'E1067:')
   call CheckDefFailure(['finally'], 'E606:')
   call CheckDefFailure(['try', 'echo 0', 'finally', 'echo 1', 'finally'], 'E607:')

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1159,
 /**/
     1158,
 /**/

src/vim9compile.c

@@ -3060,7 +3060,14 @@ compile_list(char_u **arg, cctx_T *cctx)
 	    break;
 	++count;
 	if (*p == ',')
+	{
 	    ++p;
+	    if (*p != ']' && !IS_WHITE_OR_NUL(*p))
+	    {
+		semsg(_(e_white_after), ",");
+		return FAIL;
+	    }
+	}
 	whitep = p;
 	p = skipwhite(p);
     }