[notes]
regression test for antlr/antlr4#1925

[type]
Lexer

[grammar]
lexer grammar L;
ID : ([A-Z_]|'Ā'..'\uFFFC') ([A-Z_0-9]|'Ā'..'\uFFFC')*; // FFFD+ are not valid char

[input]
均

[output]
[@0,0:0='均',<1>,1:0]
[@1,1:0='<EOF>',<-1>,1:1]