RE POSIX support in class RE (regex) does not match with POSIX characters

[ThomasH99]

On the Simulator, 7.0.235, I compile the following regex: "test:\s*([[:alpha:]][[:alnum:]]*)"

but it doesn't match for example "test: ç123".

The current test cases only tests with ASCII text strings instead of POSIX strings, so they wouldn't find this type of error.