enable FPU and implement up_fpucmp to pass ostest
With aggressive optimization enabled (-O2/-O3), ostest FPU test will fail.
This is because the compiler will generate additional vector
instructions between subsequent up_fpucmp() calls (loop vectorization
somewhere in usleep() call), which will consequently overwrite
the expected FPU context (XMM registers).
Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
3a3341ba0e