target/arm: Fix FJCVTZS vs flush-to-zero

target/arm: Fix FJCVTZS vs flush-to-zero

Input denormals cause the Javascript inexact bit
(output to Z) to be set.

Cc: qemu-stable@nongnu.org
Fixes: 6c1f6f2733a ("target/arm: Implement ARMv8.3-JSConv")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2375
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240625183536.1672454-4-richard.henderson@linaro.org
[PMM: fixed hardcoded tab in test case]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>