This reverts commit 32ad48abd7.
Unfortunately the SSE2 code here fails to compile on some versions
of gcc:
target-alpha/int_helper.c:77:24: error: invalid operands to binary >=
(have '__vector(16) unsigned char' and '__vector(16) unsigned char')
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>