win32: add support for the euro currency symbol

The euro currency symbol was added to some OEM code pages.  See:

   https://www.aivosto.com/articles/charsets-codepages-dos.html

Add a configuration option (enabled by default) to support this.
When enabled:

- The read_key() function requests wide character key events.  This
  allows the euro symbol to be entered regardless of the console OEM
  code page, though it needs to be available in the ANSI code page.

- Conversions between OEM and ANSI code pages in winansi.c are
  modified to work around a bug in the Microsoft routines.

- If the OEM code page is 850 when BusyBox starts it's changed to
  858.  This is the only currently supported OEM code page.

Also, the shell read builtin is modified to use read_key() whenever
input is being taken from the console.

1 files changed, 1 insertions, 0 deletions

diff --git a/include/mingw.h b/include/mingw.h
index 4077c8d44..4655fe511 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -485,6 +485,7 @@ void qsort_string_vector_case(char **sv, unsigned count) FAST_FUNC;
 
 const char *get_busybox_exec_path(void);
 void init_winsock(void);
+void init_codepage(void);
 
 int has_bat_suffix(const char *p);
 int has_exe_suffix(const char *p);