The instruction is "RDRAND", but the feature name, according to GCC, is
RDRND, so I had to change some macros in qsimd_p.h.
Change-Id: Icd0e0d4b27cb4e5eb892fffd14b5166779137e63
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
