The preferred way to create a constant floating point value is to use
make_float32() rather than doing a runtime int32_to_float32().
Convert the code in the VRSQRTS helper to work this way.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>