Review Request 8144553: java/lang/StackWalker/StackWalkTest.java and MultiThreadStackWalk.java fail with stack overflows

[Mandy Chung]

This is a test fix to reduce the stack depth to avoid StackOverFlow when running with -Xcomp on solaris sparc.

Webrev:
   http://cr.openjdk.java.net/~mchung/jdk9/webrevs/8144553/webrev.00/index.html

I verified the tests on solaris-sparcv9 machine with fastdebug VM -Xcomp -ea -esa.

Mandy