http://cr.openjdk.java.net/~mchung/jdk10/webrevs/8193325/webrev.00/
This fixes the bug in hotspot that sets the bci field as int but it's of short type and also StackFrameInfo to return a proper bci value. Coleen suggests not to change set_bci to take jushort but instead do the cast as in the proposed fix. The VM is in favor of C++ types and stop propagation of Java types. bci is of int in VM implementation and so be consistent.
Mandy [1] mail.openjdk.java.net/pipermail/core-libs-dev/2017-December/050581.html