SourceFile: Change the source file encoding from ISO-8859-1 to UTF-8. This is a back compat change, however the impact should be low; I don’t expect anyone to be using non-ASCII characters in strings, since no Z80 platform uses the ISO-8859-1 character encoding anyway. And for comments the file encoding does not really matter either way.
SourceBuilder: Make global scope the parent of the top-level source scope. Otherwise, labels with a name matching a globally defined symbol could not be defined on the top source level. Thanks to Santi Ontañón Villar for reporting. See https://www.msx.org/forum/msx-talk/development/glass-z80-assembler?page=15#comment-385460