8234624: jstack mixed mode should refer DWARF

[Yasumasa Suenaga]

Hi all,

I tried to get mixed stack via `jhsdb jstack --mixed`, but I couldn't.
(See JBS for details)

   https://bugs.openjdk.java.net/browse/JDK-8234624

I think it is caused by DWARF. AMD64 needs DWARF for stack unwinding, but SA does not handle it.
So I created a patch. It works fine on my Fedora 31 x64 box, but it failed on submit repo.

   http://hg.openjdk.java.net/jdk/submit/rev/f97745e0af75

Failed test was linux-x64-debug, and it is due to "gHotSpotVMTypes" was not found.
I wonder why it failed, and why my serviceability/sa tests (with fastdebug build) was succeeded.
Can you share details for this test? mach5-one-ysuenaga-JDK-8234624-20191122-0630-6909161


Thanks,

Yasumasa