Fixed a problem when lexing started at the start of a comment line so the previous character had not been set and was 0.
Fixed a problem when lexing started at the start of a comment line so the
previous character had not been set and was 0.

windoze/scintilla,windoze/scintilla,windoze/scintilla,windoze/scintilla,windoze/scintilla,windoze/scintilla,windoze/scintilla,windoze/scintilla