The std::boyer_moore_searcher is buggy for older verions of Microsoft's
STL, and missing in AppleClang's libc++ with an inefficient fall back.
Fixes: QTBUG-100236
Change-Id: Ic3cc916946546d2ef78456cd15e1425d957b989d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>