fced8ee40e
Previously, an expansion case could only start with an alpha numeric character. This commit fixes this by allowing an expansion case to start with any character except `}`. The [ICU spec](http://userguide.icu-project.org/formatparse/messages) is pretty vague: > Use a "select" argument to select sub-messages via a fixed set of keywords. It does not specify what can be a "keyword" but from looking at the surrounding syntax it appears that it can indeed be any string that does not contain a `}` character. Closes #31586 PR Close #36123