target/sparc: don't set FSR_NVA when comparing unordered floats

target/sparc: don't set FSR_NVA when comparing unordered floats

FSR_NVA should be set when one of the operands is a signaling NaN or
when using FCMPEx instructions. But those cases are already handled
within check_ieee_exception or floatxx_compare functions.
Otherwise, it should be left untouched.

FTR, this was detected by inf-compare-[5678] tests within gcc
testsuites.

Signed-off-by: Clément Chigot <chigot@adacore.com>
Message-Id: <20250425093513.863289-1-chigot@adacore.com>
Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>