patch 8.2.1284: Vim9: skipping over type includes following white space

Problem:    Vim9: skipping over type includes following white space, leading
            to an error for missing white space.
Solution:   Do not skip over white space after the type.

src/testdir/test_vim9_func.vim

@@ -283,6 +283,16 @@ def Test_call_funcref()
     assert_equal(123, Bar(Funcref))
   END
   CheckScriptSuccess(lines)
+
+  lines =<< trim END
+    vim9script
+    def UseNumber(nr: number)
+      echo nr
+    enddef
+    let Funcref: func(number) = function('UseNumber')
+    Funcref(123)
+  END
+  CheckScriptSuccess(lines)
 enddef
 
 let SomeFunc = function('len')

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1284,
 /**/
     1283,
 /**/

src/vim9compile.c

@@ -1944,7 +1944,7 @@ skip_type(char_u *start)
 		if (p[1] == ':')
 		    p = skip_type(skipwhite(p + 2));
 		else
-		    p = skipwhite(p + 1);
+		    ++p;
 	    }
 	}
 	else