[PATCH 0 of 5] Some jstack fixes and improvements

[Mark Wielaard]

Hi,

Here are some fixes and enhancements to the systemtap jstack() support.
I split them out in separate patches to make it easier to see what
changed (one of them is basically a complete reindent with a try-catch
wrapped around the body of the jstack function). These patches make
jstack() more reliable by having less hard coded constants, and better
error recovery if something still did go wrong. One patch relies on
an unreleased Systemtap 1.8 feature (@var) which adds support for
when hotspot is compiled with gcc 4.6+, it checks the systemtap version
installed to fall back on the old method (using $var) if necessary.

These are for IcedTea6. Next up is making sure everything works also
against IcedTea7.

Cheers,

Mark