When the byte sequence for a BOM occurs in the middle of a utf8 stream,
it is a ZWNBSP.
When a ZWNBSP occurs in the middle of a utf8 character sequence, and the
SIMD conversion does some work (meaning: the length is at least 16
characters long), it would not recognize the fact some charactes were
already decoded. So the conversion would then strip the ZWNBSP out,
thinking it's a BOM.
The non-SIMD conversion did not have this problem: the very first
character conversion would already set the headerdone flag.
Change-Id: I39aacf607e2e068107106254021a8042d164f628
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
1823c8f2dd