Problem: Vim9: problem calling class method from other class
Solution: Fix this problem, fix readonly object access, update error
messages.
Calling a class method from another method without the class name prefix
doesn't work properly.
A readonly object variable is modifiable outside the class using a
nested object assignment.
Remove the unused E1338 error message.
Update error messages.
closes: #13116
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>
00cd18222e
