The value of floatToRawIntBits(0.0f/0.0f) is different on x86_64 and aarch64?

[Tianhua huang]

The value of floatToRawIntBits(0.0f/0.0f) is different on x86_64 and
aarch64? Does it depends on the platform? I think the behaviour should be
same on different platforms, right?

# on x86_64
root at donotdel-openlab-allinone-l00242678:/home/ubuntu# uname -a
Linux donotdel-openlab-allinone-l00242678 4.4.0-154-generic #181-Ubuntu SMP
Tue Jun 25 05:29:03 UTC
2019 x86_64 x86_64 x86_64 GNU/Linux
scala> import java.lang.Float.floatToRawIntBits
import java.lang.Float.floatToRawIntBits
scala> floatToRawIntBits(0.0f/0.0f)
res0: Int = -4194304
scala> floatToRawIntBits(Float.NaN)
res1: Int = 2143289344

# on aarch64
[root at arm-huangtianhua spark]# uname -a
Linux arm-huangtianhua 4.14.0-49.el7a.aarch64 #1 SMP Tue Apr 10 17:22:26
UTC 2018 aarch64 aarch64 aarch64 GNU/Linux
scala> import java.lang.Float.floatToRawIntBits
import java.lang.Float.floatToRawIntBits
scala> floatToRawIntBits(0.0f/0.0f)
res1: Int = 2143289344
scala> floatToRawIntBits(Float.NaN)
res2: Int = 2143289344