Version Used: master

Steps to Reproduce:

I try to use pattern matching with Utf8String but seems that it is not yet supported.

https://sharplab.io/#v2:EYLgtghglgdgPgAQEwEYCwAoTsAuACAMQHsiUAKAJQFMIATAeRgBsBPAZQAcIYAeYFnFQB8eAM4BKTAG9MeOXgQB2MWIDuUHAGMAFrPkyM8o3gBEAMxImArgA48AXhEoANHuOngEAE7W7jvEiuhu54APoOIgAMbngAvgDcmLGY2DD4xERIZJzcfALCYpIYBkZKKqLqWrrBciUh5pa2EXguMUYmnj5N/oFt8uH+0TVxiRjJWBi4hCQAzGT8ggDaALqF0jFlomoaOjF17g1Evs2tw+2dxz1BIWHNQ0YJSUA===

Expected Behavior:

Code can be compiled.

Actual Behavior:

error CS0150: A constant value is expected