RFR: 8221658: aarch64: add necessary predicate for ubfx patterns

[Yangfei (Felix)]

Hi,

    Please review this patch adding necessary predicate for ubfx patterns in aarch64.ad.
    Bug: https://bugs.openjdk.java.net/browse/JDK-8221658
    Webrev: http://cr.openjdk.java.net/~fyang/8221658/webrev.00
    
    Currently, this issue is only reproduced with an aarch64 8u jdk. 
    Although it is not reproduced with aarch64 jdk11 or newer versions, it's better for them to have this fix. 
    Jtreg tested with aarch64 jdk8u & jdk13 fastdebug build.  Also passed the private fuzz test. 

Thanks,
Felix