patch 8.2.1183: assert_fails() checks the last error message
Problem: assert_fails() checks the last error message.
Solution: Check the first error, it is more relevant. Fix all the tests
that rely on the old behavior.
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 77ada94..5ea2945 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -746,7 +746,7 @@
def Test_unknown_function()
CheckDefExecFailure([
'let Ref: func = function("NotExist")',
- 'delfunc g:NotExist'], 'E130:')
+ 'delfunc g:NotExist'], 'E700:')
enddef
def RefFunc(Ref: func(string): string): string