RFR(XS): 8016187: assert(nbits == 32 || (-(1 << nbits-1) <= x && x < ( 1 << nbits-1))) failed: value out of range

[Morris Meyer]

Folks,

Could I get a review of this hsx24 backport change?  Its the same change 
as 8015437, which was pushed in last Friday.

Thanks much.

         --morris

WEBREV - http://cr.openjdk.java.net/~morris/JDK-8016187.01/
JBS - https://jbs.oracle.com/bugs/browse/JDK-8016187