QStaticByteArrayMatcher: enforce alignment

The data is 256 bytes, so might as well align it on a 16-byte boundary
to facilitate copying (if that happens). We should consider similar for
QByteArrayMatcher in 6.0.

Change-Id: I74966ed02f674a7295f8fffd14a8c64526d734bb
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

src/corelib/tools/qbytearraymatcher.h

@@ -85,6 +85,7 @@ private:
 
 class QStaticByteArrayMatcherBase
 {
+    Q_DECL_ALIGN(16)
     struct Skiptable {
         uchar data[256];
     } m_skiptable;