truncated multibyte characters on input.
(fhandler_console::write_replacement_char): Declare new method.
* fhandler_console.cc (CONVERT_LIMIT): Raise to 64K.
(fhandler_console::fhandler_console): Initialize trunc_buf.
(ERR): Define as independent value again.
(fhandler_console::write_replacement_char): New method to print
replacement chars.
(fhandler_console::write_normal): Add handling for truncated multibyte
sequences. Call next_char instead of pathetic CharNextExA function.
Don't change src, rather just work with found later on.
* miscfuncs.cc (is_cp_multibyte): Move here from strfuncs.cc.
Don't call Windows function, restrict to well-known ANSI/OEM codepages
and UTF-8.
(next_char): Call CharNextExA only for doublebyte codepages.
Implement for UTF-8 here.
* strfuncs.cc (is_cp_multibyte): Move to miscfuncs.cc.
* winsup.h (next_char): Declare.
* include/limits.h (MB_LEN_MAX): Set to maximum value of MB_CUR_MAX
as defined by newlib for now.