Discriminated union doesn't work with non alphabet string (e.g., Korean string 개수).

Repro steps

Provide the steps required to reproduce the problem

1. Type in the following
   type some-type =
   | 개수

Expected behavior

Should compile. Korean language doesn't have uppercase/lowercase distinction so it should just work with any Korean string.

Actual behavior

Error code FS0053 (Discriminated union cases and exception labels must be uppercase identifiers) emitted on VS 2017

Known workarounds

Prefixing the string with uppercase English letter works. e.g. U개수

Related information

Provide any related information

• Windows 10
• 4.1
• VS 2017 Community