patch 8.2.3854: Vim9: inconsistent arguments for test functions

Problem:    Vim9: inconsistent arguments for test functions.
Solution:   When :def function and script have different arguments use a list
            with two items instead of a separate function.
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 64e0bbc..156a752 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -174,7 +174,7 @@
 
   if has('float')
     call assert_equal(3, strwidth(1.2))
-    call CheckDefAndScriptFailure2(['echo strwidth(1.2)'], 'E1013: Argument 1: type mismatch, expected string but got float', 'E1174: String required for argument 1')
+    call CheckDefAndScriptFailure(['echo strwidth(1.2)'], ['E1013: Argument 1: type mismatch, expected string but got float', 'E1174: String required for argument 1'])
   endif
 
   set ambiwidth&
@@ -241,7 +241,7 @@
   call assert_fails('call str2nr({->2})', 'E729:')
   if has('float')
     call assert_equal(1, str2nr(1.2))
-    call CheckDefAndScriptFailure2(['echo str2nr(1.2)'], 'E1013: Argument 1: type mismatch, expected string but got float', 'E1174: String required for argument 1')
+    call CheckDefAndScriptFailure(['echo str2nr(1.2)'], ['E1013: Argument 1: type mismatch, expected string but got float', 'E1174: String required for argument 1'])
   endif
   call assert_fails('call str2nr(10, [])', 'E745:')
 endfunc
@@ -503,7 +503,7 @@
   call assert_fails('call simplify({})', 'E731:')
   if has('float')
     call assert_equal('1.2', simplify(1.2))
-    call CheckDefAndScriptFailure2(['echo simplify(1.2)'], 'E1013: Argument 1: type mismatch, expected string but got float', 'E1174: String required for argument 1')
+    call CheckDefAndScriptFailure(['echo simplify(1.2)'], ['E1013: Argument 1: type mismatch, expected string but got float', 'E1174: String required for argument 1'])
   endif
 endfunc