RFR 8213777: purge outdated fp code in x86_32.ad

[Eric, Chan]

Hi,

Requesting review for

Webrev : http://cr.openjdk.java.net/~phh/8213777/webrev.00/
JBS : https://bugs.openjdk.java.net/browse/JDK-8213777

I delete some outdate code in jdk-11. Since UseSSE is always larger than or equal to 2, some scenario when UseSSE  less than two is outdated.

I have tested this builds successfully .

Ensured that there are no regressions in hotspot : tier1 tests.

Regards,
Eric Chen