This is less fragile then former MultiByteToWideChar method because
second byte of BOM (0xfe) is LeadByte in Asian locales.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=39244Signed-off-by: Robert Wilhelm <robert.wilhelm@gmx.net>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>