patch 8.2.3107: Vim9: error for arguments while type didn't specify arguments

Problem:    Vim9: error for arguments while type didn't specify arguments.
Solution:   Do not update that type to check when no argument count is
            specified. (closes #8492)

src/testdir/test_vim9_assign.vim

@@ -681,6 +681,16 @@ def Test_assignment_partial()
       assert_equal('done', Partial())
   END
   CheckDefAndScriptSuccess(lines)
+
+  lines =<< trim END
+      vim9script
+      def Func(b: bool)
+      enddef
+      var Ref: func = function(Func, [true])
+      assert_equal('func()', typename(Ref))
+      Ref()
+  END
+  CheckScriptSuccess(lines)
 enddef
 
 def Test_assignment_list_any_index()

src/userfunc.c

@@ -3148,7 +3148,8 @@ call_func(
 	    argvars = argv;
 	    argcount = partial->pt_argc + argcount_in;
 
-	    if (funcexe->check_type != NULL)
+	    if (funcexe->check_type != NULL
+				     && funcexe->check_type->tt_argcount != -1)
 	    {
 		// Now funcexe->check_type is missing the added arguments, make
 		// a copy of the type with the correction.

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3107,
 /**/
     3106,
 /**/